From: Michael Neuling Date: Thu, 2 Jul 2020 04:11:16 +0000 (+1000) Subject: Add uart16550 files from fusesoc X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=aae45583d73f74ed49e0b3946e87c759e3a1c922;p=microwatt.git Add uart16550 files from fusesoc These are needed for synthesis that doesn't use fusesoc natively. These were pulled in via 'fusesoc fetch ::uart16550:1.5.5-r1' Signed-off-by: Michael Neuling --- diff --git a/uart16550/raminfr.v b/uart16550/raminfr.v new file mode 100644 index 0000000..090f751 --- /dev/null +++ b/uart16550/raminfr.v @@ -0,0 +1,111 @@ +////////////////////////////////////////////////////////////////////// +//// //// +//// raminfr.v //// +//// //// +//// //// +//// This file is part of the "UART 16550 compatible" project //// +//// http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Documentation related to this project: //// +//// - http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Projects compatibility: //// +//// - WISHBONE //// +//// RS232 Protocol //// +//// 16550D uart (mostly supported) //// +//// //// +//// Overview (main Features): //// +//// Inferrable Distributed RAM for FIFOs //// +//// //// +//// Known problems (limits): //// +//// None . //// +//// //// +//// To Do: //// +//// Nothing so far. //// +//// //// +//// Author(s): //// +//// - gorban@opencores.org //// +//// - Jacob Gorban //// +//// //// +//// Created: 2002/07/22 //// +//// Last Updated: 2002/07/22 //// +//// (See log for the revision history) //// +//// //// +//// //// +////////////////////////////////////////////////////////////////////// +//// //// +//// Copyright (C) 2000, 2001 Authors //// +//// //// +//// This source file may be used and distributed without //// +//// restriction provided that this copyright statement is not //// +//// removed from the file and that any derivative work contains //// +//// the original copyright notice and the associated disclaimer. //// +//// //// +//// This source file is free software; you can redistribute it //// +//// and/or modify it under the terms of the GNU Lesser General //// +//// Public License as published by the Free Software Foundation; //// +//// either version 2.1 of the License, or (at your option) any //// +//// later version. //// +//// //// +//// This source is distributed in the hope that it will be //// +//// useful, but WITHOUT ANY WARRANTY; without even the implied //// +//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR //// +//// PURPOSE. See the GNU Lesser General Public License for more //// +//// details. //// +//// //// +//// You should have received a copy of the GNU Lesser General //// +//// Public License along with this source; if not, download it //// +//// from http://www.opencores.org/lgpl.shtml //// +//// //// +////////////////////////////////////////////////////////////////////// +// +// CVS Revision History +// +// $Log: not supported by cvs2svn $ +// Revision 1.1 2002/07/22 23:02:23 gorban +// Bug Fixes: +// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed. +// Problem reported by Kenny.Tung. +// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers. +// +// Improvements: +// * Made FIFO's as general inferrable memory where possible. +// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx). +// This saves about 1/3 of the Slice count and reduces P&R and synthesis times. +// +// * Added optional baudrate output (baud_o). +// This is identical to BAUDOUT* signal on 16550 chip. +// It outputs 16xbit_clock_rate - the divided clock. +// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use. +// + +//Following is the Verilog code for a dual-port RAM with asynchronous read. +module raminfr + (clk, we, a, dpra, di, dpo); + +parameter addr_width = 4; +parameter data_width = 8; +parameter depth = 16; + +input clk; +input we; +input [addr_width-1:0] a; +input [addr_width-1:0] dpra; +input [data_width-1:0] di; +//output [data_width-1:0] spo; +output [data_width-1:0] dpo; +reg [data_width-1:0] ram [depth-1:0]; + +wire [data_width-1:0] dpo; +wire [data_width-1:0] di; +wire [addr_width-1:0] a; +wire [addr_width-1:0] dpra; + + always @(posedge clk) begin + if (we) + ram[a] <= di; + end +// assign spo = ram[a]; + assign dpo = ram[dpra]; +endmodule + diff --git a/uart16550/uart_defines.v b/uart16550/uart_defines.v new file mode 100644 index 0000000..fca7b6a --- /dev/null +++ b/uart16550/uart_defines.v @@ -0,0 +1,233 @@ +////////////////////////////////////////////////////////////////////// +//// //// +//// uart_defines.v //// +//// //// +//// //// +//// This file is part of the "UART 16550 compatible" project //// +//// http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Documentation related to this project: //// +//// - http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Projects compatibility: //// +//// - WISHBONE //// +//// RS232 Protocol //// +//// 16550D uart (mostly supported) //// +//// //// +//// Overview (main Features): //// +//// Defines of the Core //// +//// //// +//// Known problems (limits): //// +//// None //// +//// //// +//// To Do: //// +//// Nothing. //// +//// //// +//// Author(s): //// +//// - gorban@opencores.org //// +//// - Jacob Gorban //// +//// - Igor Mohor (igorm@opencores.org) //// +//// //// +//// Created: 2001/05/12 //// +//// Last Updated: 2001/05/17 //// +//// (See log for the revision history) //// +//// //// +//// //// +////////////////////////////////////////////////////////////////////// +//// //// +//// Copyright (C) 2000, 2001 Authors //// +//// //// +//// This source file may be used and distributed without //// +//// restriction provided that this copyright statement is not //// +//// removed from the file and that any derivative work contains //// +//// the original copyright notice and the associated disclaimer. //// +//// //// +//// This source file is free software; you can redistribute it //// +//// and/or modify it under the terms of the GNU Lesser General //// +//// Public License as published by the Free Software Foundation; //// +//// either version 2.1 of the License, or (at your option) any //// +//// later version. //// +//// //// +//// This source is distributed in the hope that it will be //// +//// useful, but WITHOUT ANY WARRANTY; without even the implied //// +//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR //// +//// PURPOSE. See the GNU Lesser General Public License for more //// +//// details. //// +//// //// +//// You should have received a copy of the GNU Lesser General //// +//// Public License along with this source; if not, download it //// +//// from http://www.opencores.org/lgpl.shtml //// +//// //// +////////////////////////////////////////////////////////////////////// +// +// CVS Revision History +// +// $Log: not supported by cvs2svn $ +// Revision 1.13 2003/06/11 16:37:47 gorban +// This fixes errors in some cases when data is being read and put to the FIFO at the same time. Patch is submitted by Scott Furman. Update is very recommended. +// +// Revision 1.12 2002/07/22 23:02:23 gorban +// Bug Fixes: +// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed. +// Problem reported by Kenny.Tung. +// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers. +// +// Improvements: +// * Made FIFO's as general inferrable memory where possible. +// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx). +// This saves about 1/3 of the Slice count and reduces P&R and synthesis times. +// +// * Added optional baudrate output (baud_o). +// This is identical to BAUDOUT* signal on 16550 chip. +// It outputs 16xbit_clock_rate - the divided clock. +// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use. +// +// Revision 1.10 2001/12/11 08:55:40 mohor +// Scratch register define added. +// +// Revision 1.9 2001/12/03 21:44:29 gorban +// Updated specification documentation. +// Added full 32-bit data bus interface, now as default. +// Address is 5-bit wide in 32-bit data bus mode. +// Added wb_sel_i input to the core. It's used in the 32-bit mode. +// Added debug interface with two 32-bit read-only registers in 32-bit mode. +// Bits 5 and 6 of LSR are now only cleared on TX FIFO write. +// My small test bench is modified to work with 32-bit mode. +// +// Revision 1.8 2001/11/26 21:38:54 gorban +// Lots of fixes: +// Break condition wasn't handled correctly at all. +// LSR bits could lose their values. +// LSR value after reset was wrong. +// Timing of THRE interrupt signal corrected. +// LSR bit 0 timing corrected. +// +// Revision 1.7 2001/08/24 21:01:12 mohor +// Things connected to parity changed. +// Clock devider changed. +// +// Revision 1.6 2001/08/23 16:05:05 mohor +// Stop bit bug fixed. +// Parity bug fixed. +// WISHBONE read cycle bug fixed, +// OE indicator (Overrun Error) bug fixed. +// PE indicator (Parity Error) bug fixed. +// Register read bug fixed. +// +// Revision 1.5 2001/05/31 20:08:01 gorban +// FIFO changes and other corrections. +// +// Revision 1.4 2001/05/21 19:12:02 gorban +// Corrected some Linter messages. +// +// Revision 1.3 2001/05/17 18:34:18 gorban +// First 'stable' release. Should be sythesizable now. Also added new header. +// +// Revision 1.0 2001-05-17 21:27:11+02 jacob +// Initial revision +// +// + +// Uncomment this if you want your UART to have +// 16xBaudrate output port. +// If defined, the enable signal will be used to drive baudrate_o signal +// It's frequency is 16xbaudrate + +// `define UART_HAS_BAUDRATE_OUTPUT + +// Register addresses +`define UART_REG_RB 3'd0 // receiver buffer +`define UART_REG_TR 3'd0 // transmitter +`define UART_REG_IE 3'd1 // Interrupt enable +`define UART_REG_II 3'd2 // Interrupt identification +`define UART_REG_FC 3'd2 // FIFO control +`define UART_REG_LC 3'd3 // Line Control +`define UART_REG_MC 3'd4 // Modem control +`define UART_REG_LS 3'd5 // Line status +`define UART_REG_MS 3'd6 // Modem status +`define UART_REG_SR 3'd7 // Scratch register +`define UART_REG_DL1 3'd0 // Divisor latch bytes (1-2) +`define UART_REG_DL2 3'd1 + +// Interrupt Enable register bits +`define UART_IE_RDA 0 // Received Data available interrupt +`define UART_IE_THRE 1 // Transmitter Holding Register empty interrupt +`define UART_IE_RLS 2 // Receiver Line Status Interrupt +`define UART_IE_MS 3 // Modem Status Interrupt + +// Interrupt Identification register bits +`define UART_II_IP 0 // Interrupt pending when 0 +`define UART_II_II 3:1 // Interrupt identification + +// Interrupt identification values for bits 3:1 +`define UART_II_RLS 3'b011 // Receiver Line Status +`define UART_II_RDA 3'b010 // Receiver Data available +`define UART_II_TI 3'b110 // Timeout Indication +`define UART_II_THRE 3'b001 // Transmitter Holding Register empty +`define UART_II_MS 3'b000 // Modem Status + +// FIFO Control Register bits +`define UART_FC_TL 1:0 // Trigger level + +// FIFO trigger level values +`define UART_FC_1 2'b00 +`define UART_FC_4 2'b01 +`define UART_FC_8 2'b10 +`define UART_FC_14 2'b11 + +// Line Control register bits +`define UART_LC_BITS 1:0 // bits in character +`define UART_LC_SB 2 // stop bits +`define UART_LC_PE 3 // parity enable +`define UART_LC_EP 4 // even parity +`define UART_LC_SP 5 // stick parity +`define UART_LC_BC 6 // Break control +`define UART_LC_DL 7 // Divisor Latch access bit + +// Modem Control register bits +`define UART_MC_DTR 0 +`define UART_MC_RTS 1 +`define UART_MC_OUT1 2 +`define UART_MC_OUT2 3 +`define UART_MC_LB 4 // Loopback mode + +// Line Status Register bits +`define UART_LS_DR 0 // Data ready +`define UART_LS_OE 1 // Overrun Error +`define UART_LS_PE 2 // Parity Error +`define UART_LS_FE 3 // Framing Error +`define UART_LS_BI 4 // Break interrupt +`define UART_LS_TFE 5 // Transmit FIFO is empty +`define UART_LS_TE 6 // Transmitter Empty indicator +`define UART_LS_EI 7 // Error indicator + +// Modem Status Register bits +`define UART_MS_DCTS 0 // Delta signals +`define UART_MS_DDSR 1 +`define UART_MS_TERI 2 +`define UART_MS_DDCD 3 +`define UART_MS_CCTS 4 // Complement signals +`define UART_MS_CDSR 5 +`define UART_MS_CRI 6 +`define UART_MS_CDCD 7 + +// FIFO parameter defines + +`define UART_FIFO_WIDTH 8 +`define UART_FIFO_DEPTH 16 +`define UART_FIFO_POINTER_W 4 +`define UART_FIFO_COUNTER_W 5 +// receiver fifo has width 11 because it has break, parity and framing error bits +`define UART_FIFO_REC_WIDTH 11 + + +`define VERBOSE_WB 0 // All activity on the WISHBONE is recorded +`define VERBOSE_LINE_STATUS 0 // Details about the lsr (line status register) +`define FAST_TEST 1 // 64/1024 packets are sent + + + + + + + diff --git a/uart16550/uart_receiver.v b/uart16550/uart_receiver.v new file mode 100644 index 0000000..44c2936 --- /dev/null +++ b/uart16550/uart_receiver.v @@ -0,0 +1,475 @@ +////////////////////////////////////////////////////////////////////// +//// //// +//// uart_receiver.v //// +//// //// +//// //// +//// This file is part of the "UART 16550 compatible" project //// +//// http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Documentation related to this project: //// +//// - http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Projects compatibility: //// +//// - WISHBONE //// +//// RS232 Protocol //// +//// 16550D uart (mostly supported) //// +//// //// +//// Overview (main Features): //// +//// UART core receiver logic //// +//// //// +//// Known problems (limits): //// +//// None known //// +//// //// +//// To Do: //// +//// Thourough testing. //// +//// //// +//// Author(s): //// +//// - gorban@opencores.org //// +//// - Jacob Gorban //// +//// - Igor Mohor (igorm@opencores.org) //// +//// //// +//// Created: 2001/05/12 //// +//// Last Updated: 2001/05/17 //// +//// (See log for the revision history) //// +//// //// +//// //// +////////////////////////////////////////////////////////////////////// +//// //// +//// Copyright (C) 2000, 2001 Authors //// +//// //// +//// This source file may be used and distributed without //// +//// restriction provided that this copyright statement is not //// +//// removed from the file and that any derivative work contains //// +//// the original copyright notice and the associated disclaimer. //// +//// //// +//// This source file is free software; you can redistribute it //// +//// and/or modify it under the terms of the GNU Lesser General //// +//// Public License as published by the Free Software Foundation; //// +//// either version 2.1 of the License, or (at your option) any //// +//// later version. //// +//// //// +//// This source is distributed in the hope that it will be //// +//// useful, but WITHOUT ANY WARRANTY; without even the implied //// +//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR //// +//// PURPOSE. See the GNU Lesser General Public License for more //// +//// details. //// +//// //// +//// You should have received a copy of the GNU Lesser General //// +//// Public License along with this source; if not, download it //// +//// from http://www.opencores.org/lgpl.shtml //// +//// //// +////////////////////////////////////////////////////////////////////// +// +// CVS Revision History +// +// $Log: not supported by cvs2svn $ +// Revision 1.29 2002/07/29 21:16:18 gorban +// The uart_defines.v file is included again in sources. +// +// Revision 1.28 2002/07/22 23:02:23 gorban +// Bug Fixes: +// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed. +// Problem reported by Kenny.Tung. +// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers. +// +// Improvements: +// * Made FIFO's as general inferrable memory where possible. +// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx). +// This saves about 1/3 of the Slice count and reduces P&R and synthesis times. +// +// * Added optional baudrate output (baud_o). +// This is identical to BAUDOUT* signal on 16550 chip. +// It outputs 16xbit_clock_rate - the divided clock. +// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use. +// +// Revision 1.27 2001/12/30 20:39:13 mohor +// More than one character was stored in case of break. End of the break +// was not detected correctly. +// +// Revision 1.26 2001/12/20 13:28:27 mohor +// Missing declaration of rf_push_q fixed. +// +// Revision 1.25 2001/12/20 13:25:46 mohor +// rx push changed to be only one cycle wide. +// +// Revision 1.24 2001/12/19 08:03:34 mohor +// Warnings cleared. +// +// Revision 1.23 2001/12/19 07:33:54 mohor +// Synplicity was having troubles with the comment. +// +// Revision 1.22 2001/12/17 14:46:48 mohor +// overrun signal was moved to separate block because many sequential lsr +// reads were preventing data from being written to rx fifo. +// underrun signal was not used and was removed from the project. +// +// Revision 1.21 2001/12/13 10:31:16 mohor +// timeout irq must be set regardless of the rda irq (rda irq does not reset the +// timeout counter). +// +// Revision 1.20 2001/12/10 19:52:05 gorban +// Igor fixed break condition bugs +// +// Revision 1.19 2001/12/06 14:51:04 gorban +// Bug in LSR[0] is fixed. +// All WISHBONE signals are now sampled, so another wait-state is introduced on all transfers. +// +// Revision 1.18 2001/12/03 21:44:29 gorban +// Updated specification documentation. +// Added full 32-bit data bus interface, now as default. +// Address is 5-bit wide in 32-bit data bus mode. +// Added wb_sel_i input to the core. It's used in the 32-bit mode. +// Added debug interface with two 32-bit read-only registers in 32-bit mode. +// Bits 5 and 6 of LSR are now only cleared on TX FIFO write. +// My small test bench is modified to work with 32-bit mode. +// +// Revision 1.17 2001/11/28 19:36:39 gorban +// Fixed: timeout and break didn't pay attention to current data format when counting time +// +// Revision 1.16 2001/11/27 22:17:09 gorban +// Fixed bug that prevented synthesis in uart_receiver.v +// +// Revision 1.15 2001/11/26 21:38:54 gorban +// Lots of fixes: +// Break condition wasn't handled correctly at all. +// LSR bits could lose their values. +// LSR value after reset was wrong. +// Timing of THRE interrupt signal corrected. +// LSR bit 0 timing corrected. +// +// Revision 1.14 2001/11/10 12:43:21 gorban +// Logic Synthesis bugs fixed. Some other minor changes +// +// Revision 1.13 2001/11/08 14:54:23 mohor +// Comments in Slovene language deleted, few small fixes for better work of +// old tools. IRQs need to be fix. +// +// Revision 1.12 2001/11/07 17:51:52 gorban +// Heavily rewritten interrupt and LSR subsystems. +// Many bugs hopefully squashed. +// +// Revision 1.11 2001/10/31 15:19:22 gorban +// Fixes to break and timeout conditions +// +// Revision 1.10 2001/10/20 09:58:40 gorban +// Small synopsis fixes +// +// Revision 1.9 2001/08/24 21:01:12 mohor +// Things connected to parity changed. +// Clock devider changed. +// +// Revision 1.8 2001/08/23 16:05:05 mohor +// Stop bit bug fixed. +// Parity bug fixed. +// WISHBONE read cycle bug fixed, +// OE indicator (Overrun Error) bug fixed. +// PE indicator (Parity Error) bug fixed. +// Register read bug fixed. +// +// Revision 1.6 2001/06/23 11:21:48 gorban +// DL made 16-bit long. Fixed transmission/reception bugs. +// +// Revision 1.5 2001/06/02 14:28:14 gorban +// Fixed receiver and transmitter. Major bug fixed. +// +// Revision 1.4 2001/05/31 20:08:01 gorban +// FIFO changes and other corrections. +// +// Revision 1.3 2001/05/27 17:37:49 gorban +// Fixed many bugs. Updated spec. Changed FIFO files structure. See CHANGES.txt file. +// +// Revision 1.2 2001/05/21 19:12:02 gorban +// Corrected some Linter messages. +// +// Revision 1.1 2001/05/17 18:34:18 gorban +// First 'stable' release. Should be sythesizable now. Also added new header. +// +// Revision 1.0 2001-05-17 21:27:11+02 jacob +// Initial revision +// +// + +`include "uart_defines.v" + +module uart_receiver (clk, wb_rst_i, lcr, rf_pop, srx_pad_i, enable, + counter_t, rf_count, rf_data_out, rf_error_bit, rf_overrun, rx_reset, lsr_mask, rstate, rf_push_pulse); + +input clk; +input wb_rst_i; +input [7:0] lcr; +input rf_pop; +input srx_pad_i; +input enable; +input rx_reset; +input lsr_mask; + +output [9:0] counter_t; +output [`UART_FIFO_COUNTER_W-1:0] rf_count; +output [`UART_FIFO_REC_WIDTH-1:0] rf_data_out; +output rf_overrun; +output rf_error_bit; +output [3:0] rstate; +output rf_push_pulse; + +reg [3:0] rstate; +reg [3:0] rcounter16; +reg [2:0] rbit_counter; +reg [7:0] rshift; // receiver shift register +reg rparity; // received parity +reg rparity_error; +reg rframing_error; // framing error flag +reg rparity_xor; +reg [7:0] counter_b; // counts the 0 (low) signals +reg rf_push_q; + +// RX FIFO signals +reg [`UART_FIFO_REC_WIDTH-1:0] rf_data_in; +wire [`UART_FIFO_REC_WIDTH-1:0] rf_data_out; +wire rf_push_pulse; +reg rf_push; +wire rf_pop; +wire rf_overrun; +wire [`UART_FIFO_COUNTER_W-1:0] rf_count; +wire rf_error_bit; // an error (parity or framing) is inside the fifo +wire break_error = (counter_b == 0); + +// RX FIFO instance +uart_rfifo #(`UART_FIFO_REC_WIDTH) fifo_rx( + .clk( clk ), + .wb_rst_i( wb_rst_i ), + .data_in( rf_data_in ), + .data_out( rf_data_out ), + .push( rf_push_pulse ), + .pop( rf_pop ), + .overrun( rf_overrun ), + .count( rf_count ), + .error_bit( rf_error_bit ), + .fifo_reset( rx_reset ), + .reset_status(lsr_mask) +); + +wire rcounter16_eq_7 = (rcounter16 == 4'd7); +wire rcounter16_eq_0 = (rcounter16 == 4'd0); + +wire [3:0] rcounter16_minus_1 = rcounter16 - 3'd1; + +parameter sr_idle = 4'd0; +parameter sr_rec_start = 4'd1; +parameter sr_rec_bit = 4'd2; +parameter sr_rec_parity = 4'd3; +parameter sr_rec_stop = 4'd4; +parameter sr_check_parity = 4'd5; +parameter sr_rec_prepare = 4'd6; +parameter sr_end_bit = 4'd7; +parameter sr_ca_lc_parity = 4'd8; +parameter sr_wait1 = 4'd9; +parameter sr_push = 4'd10; + + +always @(posedge clk or posedge wb_rst_i) +begin + if (wb_rst_i) + begin + rstate <= sr_idle; + rcounter16 <= 0; + rbit_counter <= 0; + rparity_xor <= 1'b0; + rframing_error <= 1'b0; + rparity_error <= 1'b0; + rparity <= 1'b0; + rshift <= 0; + rf_push <= 1'b0; + rf_data_in <= 0; + end + else + if (enable) + begin + case (rstate) + sr_idle : begin + rf_push <= 1'b0; + rf_data_in <= 0; + rcounter16 <= 4'b1110; + if (srx_pad_i==1'b0 & ~break_error) // detected a pulse (start bit?) + begin + rstate <= sr_rec_start; + end + end + sr_rec_start : begin + rf_push <= 1'b0; + if (rcounter16_eq_7) // check the pulse + if (srx_pad_i==1'b1) // no start bit + rstate <= sr_idle; + else // start bit detected + rstate <= sr_rec_prepare; + rcounter16 <= rcounter16_minus_1; + end + sr_rec_prepare:begin + case (lcr[/*`UART_LC_BITS*/1:0]) // number of bits in a word + 2'b00 : rbit_counter <= 3'b100; + 2'b01 : rbit_counter <= 3'b101; + 2'b10 : rbit_counter <= 3'b110; + 2'b11 : rbit_counter <= 3'b111; + endcase + if (rcounter16_eq_0) + begin + rstate <= sr_rec_bit; + rcounter16 <= 4'b1110; + rshift <= 0; + end + else + rstate <= sr_rec_prepare; + rcounter16 <= rcounter16_minus_1; + end + sr_rec_bit : begin + if (rcounter16_eq_0) + rstate <= sr_end_bit; + if (rcounter16_eq_7) // read the bit + case (lcr[/*`UART_LC_BITS*/1:0]) // number of bits in a word + 2'b00 : rshift[4:0] <= {srx_pad_i, rshift[4:1]}; + 2'b01 : rshift[5:0] <= {srx_pad_i, rshift[5:1]}; + 2'b10 : rshift[6:0] <= {srx_pad_i, rshift[6:1]}; + 2'b11 : rshift[7:0] <= {srx_pad_i, rshift[7:1]}; + endcase + rcounter16 <= rcounter16_minus_1; + end + sr_end_bit : begin + if (rbit_counter==3'b0) // no more bits in word + if (lcr[`UART_LC_PE]) // choose state based on parity + rstate <= sr_rec_parity; + else + begin + rstate <= sr_rec_stop; + rparity_error <= 1'b0; // no parity - no error :) + end + else // else we have more bits to read + begin + rstate <= sr_rec_bit; + rbit_counter <= rbit_counter - 3'd1; + end + rcounter16 <= 4'b1110; + end + sr_rec_parity: begin + if (rcounter16_eq_7) // read the parity + begin + rparity <= srx_pad_i; + rstate <= sr_ca_lc_parity; + end + rcounter16 <= rcounter16_minus_1; + end + sr_ca_lc_parity : begin // rcounter equals 6 + rcounter16 <= rcounter16_minus_1; + rparity_xor <= ^{rshift,rparity}; // calculate parity on all incoming data + rstate <= sr_check_parity; + end + sr_check_parity: begin // rcounter equals 5 + case ({lcr[`UART_LC_EP],lcr[`UART_LC_SP]}) + 2'b00: rparity_error <= rparity_xor == 0; // no error if parity 1 + 2'b01: rparity_error <= ~rparity; // parity should sticked to 1 + 2'b10: rparity_error <= rparity_xor == 1; // error if parity is odd + 2'b11: rparity_error <= rparity; // parity should be sticked to 0 + endcase + rcounter16 <= rcounter16_minus_1; + rstate <= sr_wait1; + end + sr_wait1 : if (rcounter16_eq_0) + begin + rstate <= sr_rec_stop; + rcounter16 <= 4'b1110; + end + else + rcounter16 <= rcounter16_minus_1; + sr_rec_stop : begin + if (rcounter16_eq_7) // read the parity + begin + rframing_error <= !srx_pad_i; // no framing error if input is 1 (stop bit) + rstate <= sr_push; + end + rcounter16 <= rcounter16_minus_1; + end + sr_push : begin +/////////////////////////////////////// +// $display($time, ": received: %b", rf_data_in); + if(srx_pad_i | break_error) + begin + if(break_error) + rf_data_in <= {8'b0, 3'b100}; // break input (empty character) to receiver FIFO + else + rf_data_in <= {rshift, 1'b0, rparity_error, rframing_error}; + rf_push <= 1'b1; + rstate <= sr_idle; + end + else if(~rframing_error) // There's always a framing before break_error -> wait for break or srx_pad_i + begin + rf_data_in <= {rshift, 1'b0, rparity_error, rframing_error}; + rf_push <= 1'b1; + rcounter16 <= 4'b1110; + rstate <= sr_rec_start; + end + + end + default : rstate <= sr_idle; + endcase + end // if (enable) +end // always of receiver + +always @ (posedge clk or posedge wb_rst_i) +begin + if(wb_rst_i) + rf_push_q <= 0; + else + rf_push_q <= rf_push; +end + +assign rf_push_pulse = rf_push & ~rf_push_q; + + +// +// Break condition detection. +// Works in conjuction with the receiver state machine + +reg [9:0] toc_value; // value to be set to timeout counter + +always @(lcr) + case (lcr[3:0]) + 4'b0000 : toc_value = 447; // 7 bits + 4'b0100 : toc_value = 479; // 7.5 bits + 4'b0001, 4'b1000 : toc_value = 511; // 8 bits + 4'b1100 : toc_value = 543; // 8.5 bits + 4'b0010, 4'b0101, 4'b1001 : toc_value = 575; // 9 bits + 4'b0011, 4'b0110, 4'b1010, 4'b1101 : toc_value = 639; // 10 bits + 4'b0111, 4'b1011, 4'b1110 : toc_value = 703; // 11 bits + 4'b1111 : toc_value = 767; // 12 bits + endcase // case(lcr[3:0]) + +wire [7:0] brc_value; // value to be set to break counter +assign brc_value = toc_value[9:2]; // the same as timeout but 1 insead of 4 character times + +always @(posedge clk or posedge wb_rst_i) +begin + if (wb_rst_i) + counter_b <= 8'd159; + else + if (srx_pad_i) + counter_b <= brc_value; // character time length - 1 + else + if(enable & counter_b != 8'b0) // only work on enable times break not reached. + counter_b <= counter_b - 8'd1; // decrement break counter +end // always of break condition detection + +/// +/// Timeout condition detection +reg [9:0] counter_t; // counts the timeout condition clocks + +always @(posedge clk or posedge wb_rst_i) +begin + if (wb_rst_i) + counter_t <= 10'd639; // 10 bits for the default 8N1 + else + if(rf_push_pulse || rf_pop || rf_count == 0) // counter is reset when RX FIFO is empty, accessed or above trigger level + counter_t <= toc_value; + else + if (enable && counter_t != 10'b0) // we don't want to underflow + counter_t <= counter_t - 10'd1; +end + +endmodule diff --git a/uart16550/uart_regs.v b/uart16550/uart_regs.v new file mode 100644 index 0000000..931632c --- /dev/null +++ b/uart16550/uart_regs.v @@ -0,0 +1,888 @@ +////////////////////////////////////////////////////////////////////// +//// //// +//// uart_regs.v //// +//// //// +//// //// +//// This file is part of the "UART 16550 compatible" project //// +//// http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Documentation related to this project: //// +//// - http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Projects compatibility: //// +//// - WISHBONE //// +//// RS232 Protocol //// +//// 16550D uart (mostly supported) //// +//// //// +//// Overview (main Features): //// +//// Registers of the uart 16550 core //// +//// //// +//// Known problems (limits): //// +//// Inserts 1 wait state in all WISHBONE transfers //// +//// //// +//// To Do: //// +//// Nothing or verification. //// +//// //// +//// Author(s): //// +//// - gorban@opencores.org //// +//// - Jacob Gorban //// +//// - Igor Mohor (igorm@opencores.org) //// +//// //// +//// Created: 2001/05/12 //// +//// Last Updated: (See log for the revision history //// +//// //// +//// //// +////////////////////////////////////////////////////////////////////// +//// //// +//// Copyright (C) 2000, 2001 Authors //// +//// //// +//// This source file may be used and distributed without //// +//// restriction provided that this copyright statement is not //// +//// removed from the file and that any derivative work contains //// +//// the original copyright notice and the associated disclaimer. //// +//// //// +//// This source file is free software; you can redistribute it //// +//// and/or modify it under the terms of the GNU Lesser General //// +//// Public License as published by the Free Software Foundation; //// +//// either version 2.1 of the License, or (at your option) any //// +//// later version. //// +//// //// +//// This source is distributed in the hope that it will be //// +//// useful, but WITHOUT ANY WARRANTY; without even the implied //// +//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR //// +//// PURPOSE. See the GNU Lesser General Public License for more //// +//// details. //// +//// //// +//// You should have received a copy of the GNU Lesser General //// +//// Public License along with this source; if not, download it //// +//// from http://www.opencores.org/lgpl.shtml //// +//// //// +////////////////////////////////////////////////////////////////////// +// +// CVS Revision History +// +// $Log: not supported by cvs2svn $ +// Revision 1.41 2004/05/21 11:44:41 tadejm +// Added synchronizer flops for RX input. +// +// Revision 1.40 2003/06/11 16:37:47 gorban +// This fixes errors in some cases when data is being read and put to the FIFO at the same time. Patch is submitted by Scott Furman. Update is very recommended. +// +// Revision 1.39 2002/07/29 21:16:18 gorban +// The uart_defines.v file is included again in sources. +// +// Revision 1.38 2002/07/22 23:02:23 gorban +// Bug Fixes: +// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed. +// Problem reported by Kenny.Tung. +// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers. +// +// Improvements: +// * Made FIFO's as general inferrable memory where possible. +// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx). +// This saves about 1/3 of the Slice count and reduces P&R and synthesis times. +// +// * Added optional baudrate output (baud_o). +// This is identical to BAUDOUT* signal on 16550 chip. +// It outputs 16xbit_clock_rate - the divided clock. +// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use. +// +// Revision 1.37 2001/12/27 13:24:09 mohor +// lsr[7] was not showing overrun errors. +// +// Revision 1.36 2001/12/20 13:25:46 mohor +// rx push changed to be only one cycle wide. +// +// Revision 1.35 2001/12/19 08:03:34 mohor +// Warnings cleared. +// +// Revision 1.34 2001/12/19 07:33:54 mohor +// Synplicity was having troubles with the comment. +// +// Revision 1.33 2001/12/17 10:14:43 mohor +// Things related to msr register changed. After THRE IRQ occurs, and one +// character is written to the transmit fifo, the detection of the THRE bit in the +// LSR is delayed for one character time. +// +// Revision 1.32 2001/12/14 13:19:24 mohor +// MSR register fixed. +// +// Revision 1.31 2001/12/14 10:06:58 mohor +// After reset modem status register MSR should be reset. +// +// Revision 1.30 2001/12/13 10:09:13 mohor +// thre irq should be cleared only when being source of interrupt. +// +// Revision 1.29 2001/12/12 09:05:46 mohor +// LSR status bit 0 was not cleared correctly in case of reseting the FCR (rx fifo). +// +// Revision 1.28 2001/12/10 19:52:41 gorban +// Scratch register added +// +// Revision 1.27 2001/12/06 14:51:04 gorban +// Bug in LSR[0] is fixed. +// All WISHBONE signals are now sampled, so another wait-state is introduced on all transfers. +// +// Revision 1.26 2001/12/03 21:44:29 gorban +// Updated specification documentation. +// Added full 32-bit data bus interface, now as default. +// Address is 5-bit wide in 32-bit data bus mode. +// Added wb_sel_i input to the core. It's used in the 32-bit mode. +// Added debug interface with two 32-bit read-only registers in 32-bit mode. +// Bits 5 and 6 of LSR are now only cleared on TX FIFO write. +// My small test bench is modified to work with 32-bit mode. +// +// Revision 1.25 2001/11/28 19:36:39 gorban +// Fixed: timeout and break didn't pay attention to current data format when counting time +// +// Revision 1.24 2001/11/26 21:38:54 gorban +// Lots of fixes: +// Break condition wasn't handled correctly at all. +// LSR bits could lose their values. +// LSR value after reset was wrong. +// Timing of THRE interrupt signal corrected. +// LSR bit 0 timing corrected. +// +// Revision 1.23 2001/11/12 21:57:29 gorban +// fixed more typo bugs +// +// Revision 1.22 2001/11/12 15:02:28 mohor +// lsr1r error fixed. +// +// Revision 1.21 2001/11/12 14:57:27 mohor +// ti_int_pnd error fixed. +// +// Revision 1.20 2001/11/12 14:50:27 mohor +// ti_int_d error fixed. +// +// Revision 1.19 2001/11/10 12:43:21 gorban +// Logic Synthesis bugs fixed. Some other minor changes +// +// Revision 1.18 2001/11/08 14:54:23 mohor +// Comments in Slovene language deleted, few small fixes for better work of +// old tools. IRQs need to be fix. +// +// Revision 1.17 2001/11/07 17:51:52 gorban +// Heavily rewritten interrupt and LSR subsystems. +// Many bugs hopefully squashed. +// +// Revision 1.16 2001/11/02 09:55:16 mohor +// no message +// +// Revision 1.15 2001/10/31 15:19:22 gorban +// Fixes to break and timeout conditions +// +// Revision 1.14 2001/10/29 17:00:46 gorban +// fixed parity sending and tx_fifo resets over- and underrun +// +// Revision 1.13 2001/10/20 09:58:40 gorban +// Small synopsis fixes +// +// Revision 1.12 2001/10/19 16:21:40 gorban +// Changes data_out to be synchronous again as it should have been. +// +// Revision 1.11 2001/10/18 20:35:45 gorban +// small fix +// +// Revision 1.10 2001/08/24 21:01:12 mohor +// Things connected to parity changed. +// Clock devider changed. +// +// Revision 1.9 2001/08/23 16:05:05 mohor +// Stop bit bug fixed. +// Parity bug fixed. +// WISHBONE read cycle bug fixed, +// OE indicator (Overrun Error) bug fixed. +// PE indicator (Parity Error) bug fixed. +// Register read bug fixed. +// +// Revision 1.10 2001/06/23 11:21:48 gorban +// DL made 16-bit long. Fixed transmission/reception bugs. +// +// Revision 1.9 2001/05/31 20:08:01 gorban +// FIFO changes and other corrections. +// +// Revision 1.8 2001/05/29 20:05:04 gorban +// Fixed some bugs and synthesis problems. +// +// Revision 1.7 2001/05/27 17:37:49 gorban +// Fixed many bugs. Updated spec. Changed FIFO files structure. See CHANGES.txt file. +// +// Revision 1.6 2001/05/21 19:12:02 gorban +// Corrected some Linter messages. +// +// Revision 1.5 2001/05/17 18:34:18 gorban +// First 'stable' release. Should be sythesizable now. Also added new header. +// +// Revision 1.0 2001-05-17 21:27:11+02 jacob +// Initial revision +// +// + +`include "uart_defines.v" + +`define UART_DL1 7:0 +`define UART_DL2 15:8 + +module uart_regs +#(parameter SIM = 0) + (clk, + wb_rst_i, wb_addr_i, wb_dat_i, wb_dat_o, wb_we_i, wb_re_i, + +// additional signals + modem_inputs, + stx_pad_o, srx_pad_i, + + rts_pad_o, dtr_pad_o, int_o +`ifdef UART_HAS_BAUDRATE_OUTPUT + , baud_o +`endif + + ); + +input clk; +input wb_rst_i; +input [2:0] wb_addr_i; +input [7:0] wb_dat_i; +output [7:0] wb_dat_o; +input wb_we_i; +input wb_re_i; + +output stx_pad_o; +input srx_pad_i; + +input [3:0] modem_inputs; +output rts_pad_o; +output dtr_pad_o; +output int_o; +`ifdef UART_HAS_BAUDRATE_OUTPUT +output baud_o; +`endif + +wire [3:0] modem_inputs; +reg enable; +`ifdef UART_HAS_BAUDRATE_OUTPUT +assign baud_o = enable; // baud_o is actually the enable signal +`endif + + +wire stx_pad_o; // received from transmitter module +wire srx_pad_i; +wire srx_pad; + +reg [7:0] wb_dat_o; + +wire [2:0] wb_addr_i; +wire [7:0] wb_dat_i; + + +reg [3:0] ier; +reg [3:0] iir; +reg [1:0] fcr; /// bits 7 and 6 of fcr. Other bits are ignored +reg [4:0] mcr; +reg [7:0] lcr; +reg [7:0] msr; +reg [15:0] dl; // 32-bit divisor latch +reg [7:0] scratch; // UART scratch register +reg start_dlc; // activate dlc on writing to UART_DL1 +reg lsr_mask_d; // delay for lsr_mask condition +reg msi_reset; // reset MSR 4 lower bits indicator +//reg threi_clear; // THRE interrupt clear flag +reg [15:0] dlc; // 32-bit divisor latch counter +reg int_o; + +reg [3:0] trigger_level; // trigger level of the receiver FIFO +reg rx_reset; +reg tx_reset; + +wire dlab; // divisor latch access bit +wire cts_pad_i, dsr_pad_i, ri_pad_i, dcd_pad_i; // modem status bits +wire loopback; // loopback bit (MCR bit 4) +wire cts, dsr, ri, dcd; // effective signals +wire cts_c, dsr_c, ri_c, dcd_c; // Complement effective signals (considering loopback) +wire rts_pad_o, dtr_pad_o; // modem control outputs + +// LSR bits wires and regs +wire [7:0] lsr; +wire lsr0, lsr1, lsr2, lsr3, lsr4, lsr5, lsr6, lsr7; +reg lsr0r, lsr1r, lsr2r, lsr3r, lsr4r, lsr5r, lsr6r, lsr7r; +wire lsr_mask; // lsr_mask + +// +// ASSINGS +// + +assign lsr[7:0] = { lsr7r, lsr6r, lsr5r, lsr4r, lsr3r, lsr2r, lsr1r, lsr0r }; + +assign {cts_pad_i, dsr_pad_i, ri_pad_i, dcd_pad_i} = modem_inputs; +assign {cts, dsr, ri, dcd} = ~{cts_pad_i,dsr_pad_i,ri_pad_i,dcd_pad_i}; + +assign {cts_c, dsr_c, ri_c, dcd_c} = loopback ? {mcr[`UART_MC_RTS],mcr[`UART_MC_DTR],mcr[`UART_MC_OUT1],mcr[`UART_MC_OUT2]} + : {cts_pad_i,dsr_pad_i,ri_pad_i,dcd_pad_i}; + +assign dlab = lcr[`UART_LC_DL]; +assign loopback = mcr[4]; + +// assign modem outputs +assign rts_pad_o = mcr[`UART_MC_RTS]; +assign dtr_pad_o = mcr[`UART_MC_DTR]; + +// Interrupt signals +wire rls_int; // receiver line status interrupt +wire rda_int; // receiver data available interrupt +wire ti_int; // timeout indicator interrupt +wire thre_int; // transmitter holding register empty interrupt +wire ms_int; // modem status interrupt + +// FIFO signals +reg tf_push; +reg rf_pop; +wire [`UART_FIFO_REC_WIDTH-1:0] rf_data_out; +wire rf_error_bit; // an error (parity or framing) is inside the fifo +wire rf_overrun; +wire rf_push_pulse; +wire [`UART_FIFO_COUNTER_W-1:0] rf_count; +wire [`UART_FIFO_COUNTER_W-1:0] tf_count; +wire [2:0] tstate; +wire [3:0] rstate; +wire [9:0] counter_t; + +wire thre_set_en; // THRE status is delayed one character time when a character is written to fifo. +reg [7:0] block_cnt; // While counter counts, THRE status is blocked (delayed one character cycle) +reg [7:0] block_value; // One character length minus stop bit + +// Transmitter Instance +wire serial_out; + +uart_transmitter #(.SIM (SIM)) transmitter(clk, wb_rst_i, lcr, tf_push, wb_dat_i, enable, serial_out, tstate, tf_count, tx_reset, lsr_mask); + + // Synchronizing and sampling serial RX input + uart_sync_flops i_uart_sync_flops + ( + .rst_i (wb_rst_i), + .clk_i (clk), + .stage1_rst_i (1'b0), + .stage1_clk_en_i (1'b1), + .async_dat_i (srx_pad_i), + .sync_dat_o (srx_pad) + ); + defparam i_uart_sync_flops.width = 1; + defparam i_uart_sync_flops.init_value = 1'b1; + +// handle loopback +wire serial_in = loopback ? serial_out : srx_pad; +assign stx_pad_o = loopback ? 1'b1 : serial_out; + +// Receiver Instance +uart_receiver receiver(clk, wb_rst_i, lcr, rf_pop, serial_in, enable, + counter_t, rf_count, rf_data_out, rf_error_bit, rf_overrun, rx_reset, lsr_mask, rstate, rf_push_pulse); + + +// Asynchronous reading here because the outputs are sampled in uart_wb.v file +always @(dl or dlab or ier or iir or scratch + or lcr or lsr or msr or rf_data_out or wb_addr_i or wb_re_i) // asynchrounous reading +begin + case (wb_addr_i) + `UART_REG_RB : wb_dat_o = dlab ? dl[`UART_DL1] : rf_data_out[10:3]; + `UART_REG_IE : wb_dat_o = dlab ? dl[`UART_DL2] : {4'd0,ier}; + `UART_REG_II : wb_dat_o = {4'b1100,iir}; + `UART_REG_LC : wb_dat_o = lcr; + `UART_REG_LS : wb_dat_o = lsr; + `UART_REG_MS : wb_dat_o = msr; + `UART_REG_SR : wb_dat_o = scratch; + default: wb_dat_o = 8'b0; // ?? + endcase // case(wb_addr_i) +end // always @ (dl or dlab or ier or iir or scratch... + + +// rf_pop signal handling +always @(posedge clk or posedge wb_rst_i) +begin + if (wb_rst_i) + rf_pop <= 0; + else + if (rf_pop) // restore the signal to 0 after one clock cycle + rf_pop <= 0; + else + if (wb_re_i && wb_addr_i == `UART_REG_RB && !dlab) + rf_pop <= 1; // advance read pointer +end + +wire lsr_mask_condition; +wire iir_read; +wire msr_read; +wire fifo_read; +wire fifo_write; + +assign lsr_mask_condition = (wb_re_i && wb_addr_i == `UART_REG_LS && !dlab); +assign iir_read = (wb_re_i && wb_addr_i == `UART_REG_II && !dlab); +assign msr_read = (wb_re_i && wb_addr_i == `UART_REG_MS && !dlab); +assign fifo_read = (wb_re_i && wb_addr_i == `UART_REG_RB && !dlab); +assign fifo_write = (wb_we_i && wb_addr_i == `UART_REG_TR && !dlab); + +// lsr_mask_d delayed signal handling +always @(posedge clk or posedge wb_rst_i) +begin + if (wb_rst_i) + lsr_mask_d <= 0; + else // reset bits in the Line Status Register + lsr_mask_d <= lsr_mask_condition; +end + +// lsr_mask is rise detected +assign lsr_mask = lsr_mask_condition && ~lsr_mask_d; + +// msi_reset signal handling +always @(posedge clk or posedge wb_rst_i) +begin + if (wb_rst_i) + msi_reset <= 1; + else + if (msi_reset) + msi_reset <= 0; + else + if (msr_read) + msi_reset <= 1; // reset bits in Modem Status Register +end + + +// +// WRITES AND RESETS // +// +// Line Control Register +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) + lcr <= 8'b00000011; // 8n1 setting + else + if (wb_we_i && wb_addr_i==`UART_REG_LC) + lcr <= wb_dat_i; + +// Interrupt Enable Register or UART_DL2 +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) + begin + ier <= 4'b0000; // no interrupts after reset +`ifdef PRESCALER_PRESET_HARD + dl[`UART_DL2] <= `PRESCALER_HIGH_PRESET; +`else + dl[`UART_DL2] <= 8'b0; +`endif + end + else + if (wb_we_i && wb_addr_i==`UART_REG_IE) + if (dlab) + begin + dl[`UART_DL2] <= +`ifdef PRESCALER_PRESET_HARD + dl[`UART_DL2]; +`else + wb_dat_i; +`endif + end + else + ier <= wb_dat_i[3:0]; // ier uses only 4 lsb + + +// FIFO Control Register and rx_reset, tx_reset signals +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) begin + fcr <= 2'b11; + rx_reset <= 0; + tx_reset <= 0; + end else + if (wb_we_i && wb_addr_i==`UART_REG_FC) begin + fcr <= wb_dat_i[7:6]; + rx_reset <= wb_dat_i[1]; + tx_reset <= wb_dat_i[2]; + end else begin + rx_reset <= 0; + tx_reset <= 0; + end + +// Modem Control Register +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) + mcr <= 5'b0; + else + if (wb_we_i && wb_addr_i==`UART_REG_MC) + mcr <= wb_dat_i[4:0]; + +// Scratch register +// Line Control Register +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) + scratch <= 0; // 8n1 setting + else + if (wb_we_i && wb_addr_i==`UART_REG_SR) + scratch <= wb_dat_i; + +// TX_FIFO or UART_DL1 +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) + begin +`ifdef PRESCALER_PRESET_HARD + dl[`UART_DL1] <= `PRESCALER_LOW_PRESET; +`else + dl[`UART_DL1] <= 8'b0; +`endif + tf_push <= 1'b0; + start_dlc <= 1'b0; + end + else + if (wb_we_i && wb_addr_i==`UART_REG_TR) + if (dlab) + begin +`ifdef PRESCALER_PRESET_HARD + dl[`UART_DL1] <= dl[`UART_DL1]; +`else + dl[`UART_DL1] <= wb_dat_i; +`endif + start_dlc <= 1'b1; // enable DL counter + tf_push <= 1'b0; + end + else + begin + tf_push <= 1'b1; + start_dlc <= 1'b0; + end // else: !if(dlab) + else + begin + start_dlc <= 1'b0; + tf_push <= 1'b0; + end // else: !if(dlab) + +// Receiver FIFO trigger level selection logic (asynchronous mux) +always @(fcr) + case (fcr[`UART_FC_TL]) + 2'b00 : trigger_level = 1; + 2'b01 : trigger_level = 4; + 2'b10 : trigger_level = 8; + 2'b11 : trigger_level = 14; + endcase // case(fcr[`UART_FC_TL]) + +// +// STATUS REGISTERS // +// + +// Modem Status Register +reg [3:0] delayed_modem_signals; +always @(posedge clk or posedge wb_rst_i) +begin + if (wb_rst_i) + begin + msr <= 0; + delayed_modem_signals[3:0] <= 0; + end + else begin + msr[`UART_MS_DDCD:`UART_MS_DCTS] <= msi_reset ? 4'b0 : + msr[`UART_MS_DDCD:`UART_MS_DCTS] | ({dcd, ri, dsr, cts} ^ delayed_modem_signals[3:0]); + msr[`UART_MS_CDCD:`UART_MS_CCTS] <= {dcd_c, ri_c, dsr_c, cts_c}; + delayed_modem_signals[3:0] <= {dcd, ri, dsr, cts}; + end +end + + +// Line Status Register + +// activation conditions +assign lsr0 = (rf_count==0 && rf_push_pulse); // data in receiver fifo available set condition +assign lsr1 = rf_overrun; // Receiver overrun error +assign lsr2 = rf_data_out[1]; // parity error bit +assign lsr3 = rf_data_out[0]; // framing error bit +assign lsr4 = rf_data_out[2]; // break error in the character +assign lsr5 = (tf_count==5'b0 && thre_set_en); // transmitter fifo is empty +assign lsr6 = (tf_count==5'b0 && thre_set_en && (tstate == /*`S_IDLE */ 0)); // transmitter empty +assign lsr7 = rf_error_bit | rf_overrun; + +// lsr bit0 (receiver data available) +reg lsr0_d; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr0_d <= 0; + else lsr0_d <= lsr0; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr0r <= 0; + else lsr0r <= (rf_count==1 && rf_pop && !rf_push_pulse || rx_reset) ? 1'b0 : // deassert condition + lsr0r || (lsr0 && ~lsr0_d); // set on rise of lsr0 and keep asserted until deasserted + +// lsr bit 1 (receiver overrun) +reg lsr1_d; // delayed + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr1_d <= 0; + else lsr1_d <= lsr1; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr1r <= 0; + else lsr1r <= lsr_mask ? 1'b0 : lsr1r || (lsr1 && ~lsr1_d); // set on rise + +// lsr bit 2 (parity error) +reg lsr2_d; // delayed + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr2_d <= 0; + else lsr2_d <= lsr2; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr2r <= 0; + else lsr2r <= lsr_mask ? 1'b0 : lsr2r || (lsr2 && ~lsr2_d); // set on rise + +// lsr bit 3 (framing error) +reg lsr3_d; // delayed + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr3_d <= 0; + else lsr3_d <= lsr3; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr3r <= 0; + else lsr3r <= lsr_mask ? 1'b0 : lsr3r || (lsr3 && ~lsr3_d); // set on rise + +// lsr bit 4 (break indicator) +reg lsr4_d; // delayed + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr4_d <= 0; + else lsr4_d <= lsr4; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr4r <= 0; + else lsr4r <= lsr_mask ? 1'b0 : lsr4r || (lsr4 && ~lsr4_d); + +// lsr bit 5 (transmitter fifo is empty) +reg lsr5_d; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr5_d <= 1; + else lsr5_d <= lsr5; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr5r <= 1; + else lsr5r <= (fifo_write) ? 1'b0 : lsr5r || (lsr5 && ~lsr5_d); + +// lsr bit 6 (transmitter empty indicator) +reg lsr6_d; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr6_d <= 1; + else lsr6_d <= lsr6; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr6r <= 1; + else lsr6r <= (fifo_write) ? 1'b0 : lsr6r || (lsr6 && ~lsr6_d); + +// lsr bit 7 (error in fifo) +reg lsr7_d; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr7_d <= 0; + else lsr7_d <= lsr7; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) lsr7r <= 0; + else lsr7r <= lsr_mask ? 1'b0 : lsr7r || (lsr7 && ~lsr7_d); + +// Frequency divider +always @(posedge clk or posedge wb_rst_i) +begin + if (wb_rst_i) + dlc <= 0; + else + if (start_dlc | ~ (|dlc)) + dlc <= dl - 16'd1; // preset counter + else + dlc <= dlc - 16'd1; // decrement counter +end + +// Enable signal generation logic +always @(posedge clk or posedge wb_rst_i) +begin + if (wb_rst_i) + enable <= 1'b0; + else + if (|dl & ~(|dlc)) // dl>0 & dlc==0 + enable <= 1'b1; + else + enable <= 1'b0; +end + +// Delaying THRE status for one character cycle after a character is written to an empty fifo. +always @(lcr) + case (lcr[3:0]) + 4'b0000 : block_value = 95; // 6 bits + 4'b0100 : block_value = 103; // 6.5 bits + 4'b0001, 4'b1000 : block_value = 111; // 7 bits + 4'b1100 : block_value = 119; // 7.5 bits + 4'b0010, 4'b0101, 4'b1001 : block_value = 127; // 8 bits + 4'b0011, 4'b0110, 4'b1010, 4'b1101 : block_value = 143; // 9 bits + 4'b0111, 4'b1011, 4'b1110 : block_value = 159; // 10 bits + 4'b1111 : block_value = 175; // 11 bits + endcase // case(lcr[3:0]) + +// Counting time of one character minus stop bit +always @(posedge clk or posedge wb_rst_i) +begin + if (wb_rst_i) + block_cnt <= 8'd0; + else + if(lsr5r & fifo_write) // THRE bit set & write to fifo occured + block_cnt <= SIM ? 8'd1 : block_value; + else + if (enable & block_cnt != 8'b0) // only work on enable times + block_cnt <= block_cnt - 8'd1; // decrement break counter +end // always of break condition detection + +// Generating THRE status enable signal +assign thre_set_en = ~(|block_cnt); + + +// +// INTERRUPT LOGIC +// + +assign rls_int = ier[`UART_IE_RLS] && (lsr[`UART_LS_OE] || lsr[`UART_LS_PE] || lsr[`UART_LS_FE] || lsr[`UART_LS_BI]); +assign rda_int = ier[`UART_IE_RDA] && (rf_count >= {1'b0,trigger_level}); +assign thre_int = ier[`UART_IE_THRE] && lsr[`UART_LS_TFE]; +assign ms_int = ier[`UART_IE_MS] && (| msr[3:0]); +assign ti_int = ier[`UART_IE_RDA] && (counter_t == 10'b0) && (|rf_count); + +reg rls_int_d; +reg thre_int_d; +reg ms_int_d; +reg ti_int_d; +reg rda_int_d; + +// delay lines +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) rls_int_d <= 0; + else rls_int_d <= rls_int; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) rda_int_d <= 0; + else rda_int_d <= rda_int; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) thre_int_d <= 0; + else thre_int_d <= thre_int; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) ms_int_d <= 0; + else ms_int_d <= ms_int; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) ti_int_d <= 0; + else ti_int_d <= ti_int; + +// rise detection signals + +wire rls_int_rise; +wire thre_int_rise; +wire ms_int_rise; +wire ti_int_rise; +wire rda_int_rise; + +assign rda_int_rise = rda_int & ~rda_int_d; +assign rls_int_rise = rls_int & ~rls_int_d; +assign thre_int_rise = thre_int & ~thre_int_d; +assign ms_int_rise = ms_int & ~ms_int_d; +assign ti_int_rise = ti_int & ~ti_int_d; + +// interrupt pending flags +reg rls_int_pnd; +reg rda_int_pnd; +reg thre_int_pnd; +reg ms_int_pnd; +reg ti_int_pnd; + +// interrupt pending flags assignments +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) rls_int_pnd <= 0; + else + rls_int_pnd <= lsr_mask ? 1'b0 : // reset condition + rls_int_rise ? 1'b1 : // latch condition + rls_int_pnd && ier[`UART_IE_RLS]; // default operation: remove if masked + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) rda_int_pnd <= 0; + else + rda_int_pnd <= ((rf_count == {1'b0,trigger_level}) && fifo_read) ? 1'b0 : // reset condition + rda_int_rise ? 1'b1 : // latch condition + rda_int_pnd && ier[`UART_IE_RDA]; // default operation: remove if masked + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) thre_int_pnd <= 0; + else + thre_int_pnd <= fifo_write || (iir_read & ~iir[`UART_II_IP] & iir[`UART_II_II] == `UART_II_THRE)? 1'b0 : + thre_int_rise ? 1'b1 : + thre_int_pnd && ier[`UART_IE_THRE]; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) ms_int_pnd <= 0; + else + ms_int_pnd <= msr_read ? 1'b0 : + ms_int_rise ? 1'b1 : + ms_int_pnd && ier[`UART_IE_MS]; + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) ti_int_pnd <= 0; + else + ti_int_pnd <= fifo_read ? 1'b0 : + ti_int_rise ? 1'b1 : + ti_int_pnd && ier[`UART_IE_RDA]; +// end of pending flags + +// INT_O logic +always @(posedge clk or posedge wb_rst_i) +begin + if (wb_rst_i) + int_o <= 1'b0; + else + int_o <= + rls_int_pnd ? ~lsr_mask : + rda_int_pnd ? 1'b1 : + ti_int_pnd ? ~fifo_read : + thre_int_pnd ? !(fifo_write & iir_read) : + ms_int_pnd ? ~msr_read : + 1'd0; // if no interrupt are pending +end + + +// Interrupt Identification register +always @(posedge clk or posedge wb_rst_i) +begin + if (wb_rst_i) + iir <= 1; + else + if (rls_int_pnd) // interrupt is pending + begin + iir[`UART_II_II] <= `UART_II_RLS; // set identification register to correct value + iir[`UART_II_IP] <= 1'b0; // and clear the IIR bit 0 (interrupt pending) + end else // the sequence of conditions determines priority of interrupt identification + if (rda_int) + begin + iir[`UART_II_II] <= `UART_II_RDA; + iir[`UART_II_IP] <= 1'b0; + end + else if (ti_int_pnd) + begin + iir[`UART_II_II] <= `UART_II_TI; + iir[`UART_II_IP] <= 1'b0; + end + else if (thre_int_pnd) + begin + iir[`UART_II_II] <= `UART_II_THRE; + iir[`UART_II_IP] <= 1'b0; + end + else if (ms_int_pnd) + begin + iir[`UART_II_II] <= `UART_II_MS; + iir[`UART_II_IP] <= 1'b0; + end else // no interrupt is pending + begin + iir[`UART_II_II] <= 0; + iir[`UART_II_IP] <= 1'b1; + end +end + +endmodule diff --git a/uart16550/uart_rfifo.v b/uart16550/uart_rfifo.v new file mode 100644 index 0000000..59a29b9 --- /dev/null +++ b/uart16550/uart_rfifo.v @@ -0,0 +1,316 @@ +////////////////////////////////////////////////////////////////////// +//// //// +//// uart_rfifo.v (Modified from uart_fifo.v) //// +//// //// +//// //// +//// This file is part of the "UART 16550 compatible" project //// +//// http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Documentation related to this project: //// +//// - http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Projects compatibility: //// +//// - WISHBONE //// +//// RS232 Protocol //// +//// 16550D uart (mostly supported) //// +//// //// +//// Overview (main Features): //// +//// UART core receiver FIFO //// +//// //// +//// To Do: //// +//// Nothing. //// +//// //// +//// Author(s): //// +//// - gorban@opencores.org //// +//// - Jacob Gorban //// +//// - Igor Mohor (igorm@opencores.org) //// +//// //// +//// Created: 2001/05/12 //// +//// Last Updated: 2002/07/22 //// +//// (See log for the revision history) //// +//// //// +//// //// +////////////////////////////////////////////////////////////////////// +//// //// +//// Copyright (C) 2000, 2001 Authors //// +//// //// +//// This source file may be used and distributed without //// +//// restriction provided that this copyright statement is not //// +//// removed from the file and that any derivative work contains //// +//// the original copyright notice and the associated disclaimer. //// +//// //// +//// This source file is free software; you can redistribute it //// +//// and/or modify it under the terms of the GNU Lesser General //// +//// Public License as published by the Free Software Foundation; //// +//// either version 2.1 of the License, or (at your option) any //// +//// later version. //// +//// //// +//// This source is distributed in the hope that it will be //// +//// useful, but WITHOUT ANY WARRANTY; without even the implied //// +//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR //// +//// PURPOSE. See the GNU Lesser General Public License for more //// +//// details. //// +//// //// +//// You should have received a copy of the GNU Lesser General //// +//// Public License along with this source; if not, download it //// +//// from http://www.opencores.org/lgpl.shtml //// +//// //// +////////////////////////////////////////////////////////////////////// +// +// CVS Revision History +// +// $Log: not supported by cvs2svn $ +// Revision 1.3 2003/06/11 16:37:47 gorban +// This fixes errors in some cases when data is being read and put to the FIFO at the same time. Patch is submitted by Scott Furman. Update is very recommended. +// +// Revision 1.2 2002/07/29 21:16:18 gorban +// The uart_defines.v file is included again in sources. +// +// Revision 1.1 2002/07/22 23:02:23 gorban +// Bug Fixes: +// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed. +// Problem reported by Kenny.Tung. +// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers. +// +// Improvements: +// * Made FIFO's as general inferrable memory where possible. +// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx). +// This saves about 1/3 of the Slice count and reduces P&R and synthesis times. +// +// * Added optional baudrate output (baud_o). +// This is identical to BAUDOUT* signal on 16550 chip. +// It outputs 16xbit_clock_rate - the divided clock. +// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use. +// +// Revision 1.16 2001/12/20 13:25:46 mohor +// rx push changed to be only one cycle wide. +// +// Revision 1.15 2001/12/18 09:01:07 mohor +// Bug that was entered in the last update fixed (rx state machine). +// +// Revision 1.14 2001/12/17 14:46:48 mohor +// overrun signal was moved to separate block because many sequential lsr +// reads were preventing data from being written to rx fifo. +// underrun signal was not used and was removed from the project. +// +// Revision 1.13 2001/11/26 21:38:54 gorban +// Lots of fixes: +// Break condition wasn't handled correctly at all. +// LSR bits could lose their values. +// LSR value after reset was wrong. +// Timing of THRE interrupt signal corrected. +// LSR bit 0 timing corrected. +// +// Revision 1.12 2001/11/08 14:54:23 mohor +// Comments in Slovene language deleted, few small fixes for better work of +// old tools. IRQs need to be fix. +// +// Revision 1.11 2001/11/07 17:51:52 gorban +// Heavily rewritten interrupt and LSR subsystems. +// Many bugs hopefully squashed. +// +// Revision 1.10 2001/10/20 09:58:40 gorban +// Small synopsis fixes +// +// Revision 1.9 2001/08/24 21:01:12 mohor +// Things connected to parity changed. +// Clock devider changed. +// +// Revision 1.8 2001/08/24 08:48:10 mohor +// FIFO was not cleared after the data was read bug fixed. +// +// Revision 1.7 2001/08/23 16:05:05 mohor +// Stop bit bug fixed. +// Parity bug fixed. +// WISHBONE read cycle bug fixed, +// OE indicator (Overrun Error) bug fixed. +// PE indicator (Parity Error) bug fixed. +// Register read bug fixed. +// +// Revision 1.3 2001/05/31 20:08:01 gorban +// FIFO changes and other corrections. +// +// Revision 1.3 2001/05/27 17:37:48 gorban +// Fixed many bugs. Updated spec. Changed FIFO files structure. See CHANGES.txt file. +// +// Revision 1.2 2001/05/17 18:34:18 gorban +// First 'stable' release. Should be sythesizable now. Also added new header. +// +// Revision 1.0 2001-05-17 21:27:12+02 jacob +// Initial revision +// +// + +`include "uart_defines.v" + +module uart_rfifo (clk, + wb_rst_i, data_in, data_out, +// Control signals + push, // push strobe, active high + pop, // pop strobe, active high +// status signals + overrun, + count, + error_bit, + fifo_reset, + reset_status + ); + + +// FIFO parameters +parameter fifo_width = `UART_FIFO_WIDTH; +parameter fifo_depth = `UART_FIFO_DEPTH; +parameter fifo_pointer_w = `UART_FIFO_POINTER_W; +parameter fifo_counter_w = `UART_FIFO_COUNTER_W; + +input clk; +input wb_rst_i; +input push; +input pop; +input [fifo_width-1:0] data_in; +input fifo_reset; +input reset_status; + +output [fifo_width-1:0] data_out; +output overrun; +output [fifo_counter_w-1:0] count; +output error_bit; + +wire [fifo_width-1:0] data_out; +wire [7:0] data8_out; +// flags FIFO +reg [2:0] fifo[fifo_depth-1:0]; + +// FIFO pointers +reg [fifo_pointer_w-1:0] top; +reg [fifo_pointer_w-1:0] bottom; + +reg [fifo_counter_w-1:0] count; +reg overrun; + +wire [fifo_pointer_w-1:0] top_plus_1 = top + 4'h1; + +raminfr #(fifo_pointer_w,8,fifo_depth) rfifo + (.clk(clk), + .we(push), + .a(top), + .dpra(bottom), + .di(data_in[fifo_width-1:fifo_width-8]), + .dpo(data8_out) + ); + +always @(posedge clk or posedge wb_rst_i) // synchronous FIFO +begin + if (wb_rst_i) + begin + top <= 0; + bottom <= 0; + count <= 0; + fifo[0] <= 0; + fifo[1] <= 0; + fifo[2] <= 0; + fifo[3] <= 0; + fifo[4] <= 0; + fifo[5] <= 0; + fifo[6] <= 0; + fifo[7] <= 0; + fifo[8] <= 0; + fifo[9] <= 0; + fifo[10] <= 0; + fifo[11] <= 0; + fifo[12] <= 0; + fifo[13] <= 0; + fifo[14] <= 0; + fifo[15] <= 0; + end + else + if (fifo_reset) begin + top <= 0; + bottom <= 0; + count <= 0; + fifo[0] <= 0; + fifo[1] <= 0; + fifo[2] <= 0; + fifo[3] <= 0; + fifo[4] <= 0; + fifo[5] <= 0; + fifo[6] <= 0; + fifo[7] <= 0; + fifo[8] <= 0; + fifo[9] <= 0; + fifo[10] <= 0; + fifo[11] <= 0; + fifo[12] <= 0; + fifo[13] <= 0; + fifo[14] <= 0; + fifo[15] <= 0; + end + else + begin + case ({push, pop}) + 2'b10 : if (count0) + begin + fifo[bottom] <= 0; + bottom <= bottom + 4'd1; + count <= count - 5'd1; + end + 2'b11 : begin + bottom <= bottom + 4'd1; + top <= top_plus_1; + fifo[top] <= data_in[2:0]; + end + default: ; + endcase + end +end // always + +always @(posedge clk or posedge wb_rst_i) // synchronous FIFO +begin + if (wb_rst_i) + overrun <= 1'b0; + else + if(fifo_reset | reset_status) + overrun <= 1'b0; + else + if(push & ~pop & (count==fifo_depth)) + overrun <= 1'b1; +end // always + + +// please note though that data_out is only valid one clock after pop signal +assign data_out = {data8_out,fifo[bottom]}; + +// Additional logic for detection of error conditions (parity and framing) inside the FIFO +// for the Line Status Register bit 7 + +wire [2:0] word0 = fifo[0]; +wire [2:0] word1 = fifo[1]; +wire [2:0] word2 = fifo[2]; +wire [2:0] word3 = fifo[3]; +wire [2:0] word4 = fifo[4]; +wire [2:0] word5 = fifo[5]; +wire [2:0] word6 = fifo[6]; +wire [2:0] word7 = fifo[7]; + +wire [2:0] word8 = fifo[8]; +wire [2:0] word9 = fifo[9]; +wire [2:0] word10 = fifo[10]; +wire [2:0] word11 = fifo[11]; +wire [2:0] word12 = fifo[12]; +wire [2:0] word13 = fifo[13]; +wire [2:0] word14 = fifo[14]; +wire [2:0] word15 = fifo[15]; + +// a 1 is returned if any of the error bits in the fifo is 1 +assign error_bit = |(word0[2:0] | word1[2:0] | word2[2:0] | word3[2:0] | + word4[2:0] | word5[2:0] | word6[2:0] | word7[2:0] | + word8[2:0] | word9[2:0] | word10[2:0] | word11[2:0] | + word12[2:0] | word13[2:0] | word14[2:0] | word15[2:0] ); + +endmodule diff --git a/uart16550/uart_sync_flops.v b/uart16550/uart_sync_flops.v new file mode 100644 index 0000000..82a3a61 --- /dev/null +++ b/uart16550/uart_sync_flops.v @@ -0,0 +1,117 @@ +////////////////////////////////////////////////////////////////////// +//// //// +//// uart_sync_flops.v //// +//// //// +//// //// +//// This file is part of the "UART 16550 compatible" project //// +//// http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Documentation related to this project: //// +//// - http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Projects compatibility: //// +//// - WISHBONE //// +//// RS232 Protocol //// +//// 16550D uart (mostly supported) //// +//// //// +//// Overview (main Features): //// +//// UART core receiver logic //// +//// //// +//// Known problems (limits): //// +//// None known //// +//// //// +//// To Do: //// +//// Thourough testing. //// +//// //// +//// Author(s): //// +//// - Andrej Erzen (andreje@flextronics.si) //// +//// - Tadej Markovic (tadejm@flextronics.si) //// +//// //// +//// Created: 2004/05/20 //// +//// Last Updated: 2004/05/20 //// +//// (See log for the revision history) //// +//// //// +//// //// +////////////////////////////////////////////////////////////////////// +//// //// +//// Copyright (C) 2000, 2001 Authors //// +//// //// +//// This source file may be used and distributed without //// +//// restriction provided that this copyright statement is not //// +//// removed from the file and that any derivative work contains //// +//// the original copyright notice and the associated disclaimer. //// +//// //// +//// This source file is free software; you can redistribute it //// +//// and/or modify it under the terms of the GNU Lesser General //// +//// Public License as published by the Free Software Foundation; //// +//// either version 2.1 of the License, or (at your option) any //// +//// later version. //// +//// //// +//// This source is distributed in the hope that it will be //// +//// useful, but WITHOUT ANY WARRANTY; without even the implied //// +//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR //// +//// PURPOSE. See the GNU Lesser General Public License for more //// +//// details. //// +//// //// +//// You should have received a copy of the GNU Lesser General //// +//// Public License along with this source; if not, download it //// +//// from http://www.opencores.org/lgpl.shtml //// +//// //// +////////////////////////////////////////////////////////////////////// +// +// CVS Revision History +// +// $Log: not supported by cvs2svn $ +// + +module uart_sync_flops +( + // internal signals + rst_i, + clk_i, + stage1_rst_i, + stage1_clk_en_i, + async_dat_i, + sync_dat_o +); + +parameter width = 1; +parameter init_value = 1'b0; + +input rst_i; // reset input +input clk_i; // clock input +input stage1_rst_i; // synchronous reset for stage 1 FF +input stage1_clk_en_i; // synchronous clock enable for stage 1 FF +input [width-1:0] async_dat_i; // asynchronous data input +output [width-1:0] sync_dat_o; // synchronous data output + + +// +// Interal signal declarations +// + +reg [width-1:0] sync_dat_o; +reg [width-1:0] flop_0; + + +// first stage +always @ (posedge clk_i or posedge rst_i) +begin + if (rst_i) + flop_0 <= {width{init_value}}; + else + flop_0 <= async_dat_i; +end + +// second stage +always @ (posedge clk_i or posedge rst_i) +begin + if (rst_i) + sync_dat_o <= {width{init_value}}; + else if (stage1_rst_i) + sync_dat_o <= {width{init_value}}; + else if (stage1_clk_en_i) + sync_dat_o <= flop_0; +end + +endmodule diff --git a/uart16550/uart_tfifo.v b/uart16550/uart_tfifo.v new file mode 100644 index 0000000..5b254cb --- /dev/null +++ b/uart16550/uart_tfifo.v @@ -0,0 +1,239 @@ +////////////////////////////////////////////////////////////////////// +//// //// +//// uart_tfifo.v //// +//// //// +//// //// +//// This file is part of the "UART 16550 compatible" project //// +//// http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Documentation related to this project: //// +//// - http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Projects compatibility: //// +//// - WISHBONE //// +//// RS232 Protocol //// +//// 16550D uart (mostly supported) //// +//// //// +//// Overview (main Features): //// +//// UART core transmitter FIFO //// +//// //// +//// To Do: //// +//// Nothing. //// +//// //// +//// Author(s): //// +//// - gorban@opencores.org //// +//// - Jacob Gorban //// +//// - Igor Mohor (igorm@opencores.org) //// +//// //// +//// Created: 2001/05/12 //// +//// Last Updated: 2002/07/22 //// +//// (See log for the revision history) //// +//// //// +//// //// +////////////////////////////////////////////////////////////////////// +//// //// +//// Copyright (C) 2000, 2001 Authors //// +//// //// +//// This source file may be used and distributed without //// +//// restriction provided that this copyright statement is not //// +//// removed from the file and that any derivative work contains //// +//// the original copyright notice and the associated disclaimer. //// +//// //// +//// This source file is free software; you can redistribute it //// +//// and/or modify it under the terms of the GNU Lesser General //// +//// Public License as published by the Free Software Foundation; //// +//// either version 2.1 of the License, or (at your option) any //// +//// later version. //// +//// //// +//// This source is distributed in the hope that it will be //// +//// useful, but WITHOUT ANY WARRANTY; without even the implied //// +//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR //// +//// PURPOSE. See the GNU Lesser General Public License for more //// +//// details. //// +//// //// +//// You should have received a copy of the GNU Lesser General //// +//// Public License along with this source; if not, download it //// +//// from http://www.opencores.org/lgpl.shtml //// +//// //// +////////////////////////////////////////////////////////////////////// +// +// CVS Revision History +// +// $Log: not supported by cvs2svn $ +// Revision 1.1 2002/07/22 23:02:23 gorban +// Bug Fixes: +// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed. +// Problem reported by Kenny.Tung. +// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers. +// +// Improvements: +// * Made FIFO's as general inferrable memory where possible. +// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx). +// This saves about 1/3 of the Slice count and reduces P&R and synthesis times. +// +// * Added optional baudrate output (baud_o). +// This is identical to BAUDOUT* signal on 16550 chip. +// It outputs 16xbit_clock_rate - the divided clock. +// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use. +// +// Revision 1.16 2001/12/20 13:25:46 mohor +// rx push changed to be only one cycle wide. +// +// Revision 1.15 2001/12/18 09:01:07 mohor +// Bug that was entered in the last update fixed (rx state machine). +// +// Revision 1.14 2001/12/17 14:46:48 mohor +// overrun signal was moved to separate block because many sequential lsr +// reads were preventing data from being written to rx fifo. +// underrun signal was not used and was removed from the project. +// +// Revision 1.13 2001/11/26 21:38:54 gorban +// Lots of fixes: +// Break condition wasn't handled correctly at all. +// LSR bits could lose their values. +// LSR value after reset was wrong. +// Timing of THRE interrupt signal corrected. +// LSR bit 0 timing corrected. +// +// Revision 1.12 2001/11/08 14:54:23 mohor +// Comments in Slovene language deleted, few small fixes for better work of +// old tools. IRQs need to be fix. +// +// Revision 1.11 2001/11/07 17:51:52 gorban +// Heavily rewritten interrupt and LSR subsystems. +// Many bugs hopefully squashed. +// +// Revision 1.10 2001/10/20 09:58:40 gorban +// Small synopsis fixes +// +// Revision 1.9 2001/08/24 21:01:12 mohor +// Things connected to parity changed. +// Clock devider changed. +// +// Revision 1.8 2001/08/24 08:48:10 mohor +// FIFO was not cleared after the data was read bug fixed. +// +// Revision 1.7 2001/08/23 16:05:05 mohor +// Stop bit bug fixed. +// Parity bug fixed. +// WISHBONE read cycle bug fixed, +// OE indicator (Overrun Error) bug fixed. +// PE indicator (Parity Error) bug fixed. +// Register read bug fixed. +// +// Revision 1.3 2001/05/31 20:08:01 gorban +// FIFO changes and other corrections. +// +// Revision 1.3 2001/05/27 17:37:48 gorban +// Fixed many bugs. Updated spec. Changed FIFO files structure. See CHANGES.txt file. +// +// Revision 1.2 2001/05/17 18:34:18 gorban +// First 'stable' release. Should be sythesizable now. Also added new header. +// +// Revision 1.0 2001-05-17 21:27:12+02 jacob +// Initial revision +// +// + +`include "uart_defines.v" + +module uart_tfifo (clk, + wb_rst_i, data_in, data_out, +// Control signals + push, // push strobe, active high + pop, // pop strobe, active high +// status signals + overrun, + count, + fifo_reset, + reset_status + ); + + +// FIFO parameters +parameter fifo_width = `UART_FIFO_WIDTH; +parameter fifo_depth = `UART_FIFO_DEPTH; +parameter fifo_pointer_w = `UART_FIFO_POINTER_W; +parameter fifo_counter_w = `UART_FIFO_COUNTER_W; + +input clk; +input wb_rst_i; +input push; +input pop; +input [fifo_width-1:0] data_in; +input fifo_reset; +input reset_status; + +output [fifo_width-1:0] data_out; +output overrun; +output [fifo_counter_w-1:0] count; + +wire [fifo_width-1:0] data_out; + +// FIFO pointers +reg [fifo_pointer_w-1:0] top; +reg [fifo_pointer_w-1:0] bottom; + +reg [fifo_counter_w-1:0] count; +reg overrun; +wire [fifo_pointer_w-1:0] top_plus_1 = top + 4'd1; + +raminfr #(fifo_pointer_w,fifo_width,fifo_depth) tfifo + (.clk(clk), + .we(push), + .a(top), + .dpra(bottom), + .di(data_in), + .dpo(data_out) + ); + + +always @(posedge clk or posedge wb_rst_i) // synchronous FIFO +begin + if (wb_rst_i) + begin + top <= 0; + bottom <= 0; + count <= 0; + end + else + if (fifo_reset) begin + top <= 0; + bottom <= 0; + count <= 0; + end + else + begin + case ({push, pop}) + 2'b10 : if (count0) + begin + bottom <= bottom + 4'd1; + count <= count - 5'd1; + end + 2'b11 : begin + bottom <= bottom + 4'd1; + top <= top_plus_1; + end + default: ; + endcase + end +end // always + +always @(posedge clk or posedge wb_rst_i) // synchronous FIFO +begin + if (wb_rst_i) + overrun <= 1'b0; + else + if(fifo_reset | reset_status) + overrun <= 1'b0; + else + if(push & (count==fifo_depth)) + overrun <= 1'b1; +end // always + +endmodule diff --git a/uart16550/uart_top.v b/uart16550/uart_top.v new file mode 100644 index 0000000..528f2f7 --- /dev/null +++ b/uart16550/uart_top.v @@ -0,0 +1,261 @@ +////////////////////////////////////////////////////////////////////// +//// //// +//// uart_top.v //// +//// //// +//// //// +//// This file is part of the "UART 16550 compatible" project //// +//// http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Documentation related to this project: //// +//// - http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Projects compatibility: //// +//// - WISHBONE //// +//// RS232 Protocol //// +//// 16550D uart (mostly supported) //// +//// //// +//// Overview (main Features): //// +//// UART core top level. //// +//// //// +//// Known problems (limits): //// +//// Note that transmitter and receiver instances are inside //// +//// the uart_regs.v file. //// +//// //// +//// To Do: //// +//// Nothing so far. //// +//// //// +//// Author(s): //// +//// - gorban@opencores.org //// +//// - Jacob Gorban //// +//// - Igor Mohor (igorm@opencores.org) //// +//// //// +//// Created: 2001/05/12 //// +//// Last Updated: 2001/05/17 //// +//// (See log for the revision history) //// +//// //// +//// //// +////////////////////////////////////////////////////////////////////// +//// //// +//// Copyright (C) 2000, 2001 Authors //// +//// //// +//// This source file may be used and distributed without //// +//// restriction provided that this copyright statement is not //// +//// removed from the file and that any derivative work contains //// +//// the original copyright notice and the associated disclaimer. //// +//// //// +//// This source file is free software; you can redistribute it //// +//// and/or modify it under the terms of the GNU Lesser General //// +//// Public License as published by the Free Software Foundation; //// +//// either version 2.1 of the License, or (at your option) any //// +//// later version. //// +//// //// +//// This source is distributed in the hope that it will be //// +//// useful, but WITHOUT ANY WARRANTY; without even the implied //// +//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR //// +//// PURPOSE. See the GNU Lesser General Public License for more //// +//// details. //// +//// //// +//// You should have received a copy of the GNU Lesser General //// +//// Public License along with this source; if not, download it //// +//// from http://www.opencores.org/lgpl.shtml //// +//// //// +////////////////////////////////////////////////////////////////////// +// +// CVS Revision History +// +// $Log: not supported by cvs2svn $ +// Revision 1.18 2002/07/22 23:02:23 gorban +// Bug Fixes: +// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed. +// Problem reported by Kenny.Tung. +// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers. +// +// Improvements: +// * Made FIFO's as general inferrable memory where possible. +// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx). +// This saves about 1/3 of the Slice count and reduces P&R and synthesis times. +// +// * Added optional baudrate output (baud_o). +// This is identical to BAUDOUT* signal on 16550 chip. +// It outputs 16xbit_clock_rate - the divided clock. +// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use. +// +// Revision 1.17 2001/12/19 08:40:03 mohor +// Warnings fixed (unused signals removed). +// +// Revision 1.16 2001/12/06 14:51:04 gorban +// Bug in LSR[0] is fixed. +// All WISHBONE signals are now sampled, so another wait-state is introduced on all transfers. +// +// Revision 1.15 2001/12/03 21:44:29 gorban +// Updated specification documentation. +// Added full 32-bit data bus interface, now as default. +// Address is 5-bit wide in 32-bit data bus mode. +// Added wb_sel_i input to the core. It's used in the 32-bit mode. +// Added debug interface with two 32-bit read-only registers in 32-bit mode. +// Bits 5 and 6 of LSR are now only cleared on TX FIFO write. +// My small test bench is modified to work with 32-bit mode. +// +// Revision 1.14 2001/11/07 17:51:52 gorban +// Heavily rewritten interrupt and LSR subsystems. +// Many bugs hopefully squashed. +// +// Revision 1.13 2001/10/20 09:58:40 gorban +// Small synopsis fixes +// +// Revision 1.12 2001/08/25 15:46:19 gorban +// Modified port names again +// +// Revision 1.11 2001/08/24 21:01:12 mohor +// Things connected to parity changed. +// Clock devider changed. +// +// Revision 1.10 2001/08/23 16:05:05 mohor +// Stop bit bug fixed. +// Parity bug fixed. +// WISHBONE read cycle bug fixed, +// OE indicator (Overrun Error) bug fixed. +// PE indicator (Parity Error) bug fixed. +// Register read bug fixed. +// +// Revision 1.4 2001/05/31 20:08:01 gorban +// FIFO changes and other corrections. +// +// Revision 1.3 2001/05/21 19:12:02 gorban +// Corrected some Linter messages. +// +// Revision 1.2 2001/05/17 18:34:18 gorban +// First 'stable' release. Should be sythesizable now. Also added new header. +// +// Revision 1.0 2001-05-17 21:27:12+02 jacob +// Initial revision +// +// + +`include "uart_defines.v" + +module uart_top ( + wb_clk_i, + + // Wishbone signals + wb_rst_i, wb_adr_i, wb_dat_i, wb_dat_o, wb_we_i, wb_stb_i, wb_cyc_i, wb_ack_o, wb_sel_i, + int_o, // interrupt request + + // UART signals + // serial input/output + stx_pad_o, srx_pad_i, + + // modem signals + rts_pad_o, cts_pad_i, dtr_pad_o, dsr_pad_i, ri_pad_i, dcd_pad_i +`ifdef UART_HAS_BAUDRATE_OUTPUT + , baud_o +`endif + ); +parameter SIM = 0; +parameter debug = 0; + +input wb_clk_i; + +// WISHBONE interface +input wb_rst_i; +input [2:0] wb_adr_i; +input [7:0] wb_dat_i; +output [7:0] wb_dat_o; +input wb_we_i; +input wb_stb_i; +input wb_cyc_i; +input [3:0] wb_sel_i; +output wb_ack_o; +output int_o; + +// UART signals +input srx_pad_i; +output stx_pad_o; +output rts_pad_o; +input cts_pad_i; +output dtr_pad_o; +input dsr_pad_i; +input ri_pad_i; +input dcd_pad_i; + +// optional baudrate output +`ifdef UART_HAS_BAUDRATE_OUTPUT +output baud_o; +`endif + + +wire stx_pad_o; +wire rts_pad_o; +wire dtr_pad_o; + +wire [2:0] wb_adr_i; +wire [7:0] wb_dat_i; +wire [7:0] wb_dat_o; + +wire [7:0] wb_dat8_i; // 8-bit internal data input +wire [7:0] wb_dat8_o; // 8-bit internal data output +wire [31:0] wb_dat32_o; // debug interface 32-bit output +wire [3:0] wb_sel_i; // WISHBONE select signal +wire [2:0] wb_adr_int; +wire we_o; // Write enable for registers +wire re_o; // Read enable for registers +// +// MODULE INSTANCES +// + +//// WISHBONE interface module +uart_wb wb_interface( + .clk( wb_clk_i ), + .wb_rst_i( wb_rst_i ), + .wb_dat_i(wb_dat_i), + .wb_dat_o(wb_dat_o), + .wb_dat8_i(wb_dat8_i), + .wb_dat8_o(wb_dat8_o), + .wb_dat32_o(32'b0), + .wb_sel_i(4'b0), + .wb_we_i( wb_we_i ), + .wb_stb_i( wb_stb_i ), + .wb_cyc_i( wb_cyc_i ), + .wb_ack_o( wb_ack_o ), + .wb_adr_i(wb_adr_i), + .wb_adr_int(wb_adr_int), + .we_o( we_o ), + .re_o(re_o) + ); + +// Registers +uart_regs #(.SIM (SIM)) regs( + .clk( wb_clk_i ), + .wb_rst_i( wb_rst_i ), + .wb_addr_i( wb_adr_int ), + .wb_dat_i( wb_dat8_i ), + .wb_dat_o( wb_dat8_o ), + .wb_we_i( we_o ), + .wb_re_i(re_o), + .modem_inputs( {cts_pad_i, dsr_pad_i, + ri_pad_i, dcd_pad_i} ), + .stx_pad_o( stx_pad_o ), + .srx_pad_i( srx_pad_i ), + .rts_pad_o( rts_pad_o ), + .dtr_pad_o( dtr_pad_o ), + .int_o( int_o ) +`ifdef UART_HAS_BAUDRATE_OUTPUT + , .baud_o(baud_o) +`endif + +); + +initial +begin + if(debug) begin + `ifdef UART_HAS_BAUDRATE_OUTPUT + $display("(%m) UART INFO: Has baudrate output\n"); + `else + $display("(%m) UART INFO: Doesn't have baudrate output\n"); + `endif + end +end + +endmodule + + diff --git a/uart16550/uart_transmitter.v b/uart16550/uart_transmitter.v new file mode 100644 index 0000000..e2e8cf3 --- /dev/null +++ b/uart16550/uart_transmitter.v @@ -0,0 +1,354 @@ +////////////////////////////////////////////////////////////////////// +//// //// +//// uart_transmitter.v //// +//// //// +//// //// +//// This file is part of the "UART 16550 compatible" project //// +//// http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Documentation related to this project: //// +//// - http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Projects compatibility: //// +//// - WISHBONE //// +//// RS232 Protocol //// +//// 16550D uart (mostly supported) //// +//// //// +//// Overview (main Features): //// +//// UART core transmitter logic //// +//// //// +//// Known problems (limits): //// +//// None known //// +//// //// +//// To Do: //// +//// Thourough testing. //// +//// //// +//// Author(s): //// +//// - gorban@opencores.org //// +//// - Jacob Gorban //// +//// - Igor Mohor (igorm@opencores.org) //// +//// //// +//// Created: 2001/05/12 //// +//// Last Updated: 2001/05/17 //// +//// (See log for the revision history) //// +//// //// +//// //// +////////////////////////////////////////////////////////////////////// +//// //// +//// Copyright (C) 2000, 2001 Authors //// +//// //// +//// This source file may be used and distributed without //// +//// restriction provided that this copyright statement is not //// +//// removed from the file and that any derivative work contains //// +//// the original copyright notice and the associated disclaimer. //// +//// //// +//// This source file is free software; you can redistribute it //// +//// and/or modify it under the terms of the GNU Lesser General //// +//// Public License as published by the Free Software Foundation; //// +//// either version 2.1 of the License, or (at your option) any //// +//// later version. //// +//// //// +//// This source is distributed in the hope that it will be //// +//// useful, but WITHOUT ANY WARRANTY; without even the implied //// +//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR //// +//// PURPOSE. See the GNU Lesser General Public License for more //// +//// details. //// +//// //// +//// You should have received a copy of the GNU Lesser General //// +//// Public License along with this source; if not, download it //// +//// from http://www.opencores.org/lgpl.shtml //// +//// //// +////////////////////////////////////////////////////////////////////// +// +// CVS Revision History +// +// $Log: not supported by cvs2svn $ +// Revision 1.18 2002/07/22 23:02:23 gorban +// Bug Fixes: +// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed. +// Problem reported by Kenny.Tung. +// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers. +// +// Improvements: +// * Made FIFO's as general inferrable memory where possible. +// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx). +// This saves about 1/3 of the Slice count and reduces P&R and synthesis times. +// +// * Added optional baudrate output (baud_o). +// This is identical to BAUDOUT* signal on 16550 chip. +// It outputs 16xbit_clock_rate - the divided clock. +// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use. +// +// Revision 1.16 2002/01/08 11:29:40 mohor +// tf_pop was too wide. Now it is only 1 clk cycle width. +// +// Revision 1.15 2001/12/17 14:46:48 mohor +// overrun signal was moved to separate block because many sequential lsr +// reads were preventing data from being written to rx fifo. +// underrun signal was not used and was removed from the project. +// +// Revision 1.14 2001/12/03 21:44:29 gorban +// Updated specification documentation. +// Added full 32-bit data bus interface, now as default. +// Address is 5-bit wide in 32-bit data bus mode. +// Added wb_sel_i input to the core. It's used in the 32-bit mode. +// Added debug interface with two 32-bit read-only registers in 32-bit mode. +// Bits 5 and 6 of LSR are now only cleared on TX FIFO write. +// My small test bench is modified to work with 32-bit mode. +// +// Revision 1.13 2001/11/08 14:54:23 mohor +// Comments in Slovene language deleted, few small fixes for better work of +// old tools. IRQs need to be fix. +// +// Revision 1.12 2001/11/07 17:51:52 gorban +// Heavily rewritten interrupt and LSR subsystems. +// Many bugs hopefully squashed. +// +// Revision 1.11 2001/10/29 17:00:46 gorban +// fixed parity sending and tx_fifo resets over- and underrun +// +// Revision 1.10 2001/10/20 09:58:40 gorban +// Small synopsis fixes +// +// Revision 1.9 2001/08/24 21:01:12 mohor +// Things connected to parity changed. +// Clock devider changed. +// +// Revision 1.8 2001/08/23 16:05:05 mohor +// Stop bit bug fixed. +// Parity bug fixed. +// WISHBONE read cycle bug fixed, +// OE indicator (Overrun Error) bug fixed. +// PE indicator (Parity Error) bug fixed. +// Register read bug fixed. +// +// Revision 1.6 2001/06/23 11:21:48 gorban +// DL made 16-bit long. Fixed transmission/reception bugs. +// +// Revision 1.5 2001/06/02 14:28:14 gorban +// Fixed receiver and transmitter. Major bug fixed. +// +// Revision 1.4 2001/05/31 20:08:01 gorban +// FIFO changes and other corrections. +// +// Revision 1.3 2001/05/27 17:37:49 gorban +// Fixed many bugs. Updated spec. Changed FIFO files structure. See CHANGES.txt file. +// +// Revision 1.2 2001/05/21 19:12:02 gorban +// Corrected some Linter messages. +// +// Revision 1.1 2001/05/17 18:34:18 gorban +// First 'stable' release. Should be sythesizable now. Also added new header. +// +// Revision 1.0 2001-05-17 21:27:12+02 jacob +// Initial revision +// +// + +`include "uart_defines.v" + +module uart_transmitter +#(parameter SIM = 0) + (clk, wb_rst_i, lcr, tf_push, wb_dat_i, enable, stx_pad_o, tstate, tf_count, tx_reset, lsr_mask); + +input clk; +input wb_rst_i; +input [7:0] lcr; +input tf_push; +input [7:0] wb_dat_i; +input enable; +input tx_reset; +input lsr_mask; //reset of fifo +output stx_pad_o; +output [2:0] tstate; +output [`UART_FIFO_COUNTER_W-1:0] tf_count; + +reg [2:0] tstate; +reg [4:0] counter; +reg [2:0] bit_counter; // counts the bits to be sent +reg [6:0] shift_out; // output shift register +reg stx_o_tmp; +reg parity_xor; // parity of the word +reg tf_pop; +reg bit_out; + +// TX FIFO instance +// +// Transmitter FIFO signals +wire [`UART_FIFO_WIDTH-1:0] tf_data_in; +wire [`UART_FIFO_WIDTH-1:0] tf_data_out; +wire tf_push; +wire tf_overrun; +wire [`UART_FIFO_COUNTER_W-1:0] tf_count; + +assign tf_data_in = wb_dat_i; + +uart_tfifo fifo_tx( // error bit signal is not used in transmitter FIFO + .clk( clk ), + .wb_rst_i( wb_rst_i ), + .data_in( tf_data_in ), + .data_out( tf_data_out ), + .push( tf_push ), + .pop( tf_pop ), + .overrun( tf_overrun ), + .count( tf_count ), + .fifo_reset( tx_reset ), + .reset_status(lsr_mask) +); + +// TRANSMITTER FINAL STATE MACHINE + +localparam s_idle = 3'd0; +localparam s_send_start = 3'd1; +localparam s_send_byte = 3'd2; +localparam s_send_parity = 3'd3; +localparam s_send_stop = 3'd4; +localparam s_pop_byte = 3'd5; + +always @(posedge clk or posedge wb_rst_i) +begin + if (wb_rst_i) + begin + tstate <= s_idle; + stx_o_tmp <= 1'b1; + counter <= 5'b0; + shift_out <= 7'b0; + bit_out <= 1'b0; + parity_xor <= 1'b0; + tf_pop <= 1'b0; + bit_counter <= 3'b0; + end + else + if (enable | SIM) + begin + case (tstate) + s_idle : if (~|tf_count) // if tf_count==0 + begin + tstate <= s_idle; + stx_o_tmp <= 1'b1; + end + else + begin + tf_pop <= 1'b0; + stx_o_tmp <= 1'b1; + tstate <= s_pop_byte; + end + s_pop_byte : begin + tf_pop <= 1'b1; + case (lcr[/*`UART_LC_BITS*/1:0]) // number of bits in a word + 2'b00 : begin + bit_counter <= 3'b100; + parity_xor <= ^tf_data_out[4:0]; + end + 2'b01 : begin + bit_counter <= 3'b101; + parity_xor <= ^tf_data_out[5:0]; + end + 2'b10 : begin + bit_counter <= 3'b110; + parity_xor <= ^tf_data_out[6:0]; + end + 2'b11 : begin + bit_counter <= 3'b111; + parity_xor <= ^tf_data_out[7:0]; + end + endcase + {shift_out[6:0], bit_out} <= tf_data_out; + tstate <= s_send_start; + end + s_send_start : begin + tf_pop <= 1'b0; + if (~|counter) + counter <= 5'b01111; + else + if (counter == 5'b00001) + begin + counter <= 0; + tstate <= s_send_byte; + end + else + counter <= counter - 5'd1; + stx_o_tmp <= 1'b0; + if (SIM) begin + tstate <= s_idle; + $write("%c", tf_data_out); + $fflush(32'h80000001); + end + end + s_send_byte : begin + if (~|counter) + counter <= 5'b01111; + else + if (counter == 5'b00001) + begin + if (bit_counter > 3'b0) + begin + bit_counter <= bit_counter - 3'd1; + {shift_out[5:0],bit_out } <= {shift_out[6:1], shift_out[0]}; + tstate <= s_send_byte; + end + else // end of byte + if (~lcr[`UART_LC_PE]) + begin + tstate <= s_send_stop; + end + else + begin + case ({lcr[`UART_LC_EP],lcr[`UART_LC_SP]}) + 2'b00: bit_out <= ~parity_xor; + 2'b01: bit_out <= 1'b1; + 2'b10: bit_out <= parity_xor; + 2'b11: bit_out <= 1'b0; + endcase + tstate <= s_send_parity; + end + counter <= 0; + end + else + counter <= counter - 5'd1; + stx_o_tmp <= bit_out; // set output pin + end + s_send_parity : begin + if (~|counter) + counter <= 5'b01111; + else + if (counter == 5'b00001) + begin + counter <= 5'd0; + tstate <= s_send_stop; + end + else + counter <= counter - 5'd1; + stx_o_tmp <= bit_out; + end + s_send_stop : begin + if (~|counter) + begin + casez ({lcr[`UART_LC_SB],lcr[`UART_LC_BITS]}) + 3'b0??: counter <= 5'b01101; // 1 stop bit ok igor + 3'b100: counter <= 5'b10101; // 1.5 stop bit + default: counter <= 5'b11101; // 2 stop bits + endcase + end + else + if (counter == 5'b00001) + begin + counter <= 0; + tstate <= s_idle; + end + else + counter <= counter - 5'd1; + stx_o_tmp <= 1'b1; + end + + default : // should never get here + tstate <= s_idle; + endcase + end // end if enable + else + tf_pop <= 1'b0; // tf_pop must be 1 cycle width +end // transmitter logic + +assign stx_pad_o = lcr[`UART_LC_BC] ? 1'b0 : stx_o_tmp; // Break condition + +endmodule diff --git a/uart16550/uart_wb.v b/uart16550/uart_wb.v new file mode 100644 index 0000000..d537b70 --- /dev/null +++ b/uart16550/uart_wb.v @@ -0,0 +1,258 @@ +////////////////////////////////////////////////////////////////////// +//// //// +//// uart_wb.v //// +//// //// +//// //// +//// This file is part of the "UART 16550 compatible" project //// +//// http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Documentation related to this project: //// +//// - http://www.opencores.org/cores/uart16550/ //// +//// //// +//// Projects compatibility: //// +//// - WISHBONE //// +//// RS232 Protocol //// +//// 16550D uart (mostly supported) //// +//// //// +//// Overview (main Features): //// +//// UART core WISHBONE interface. //// +//// //// +//// Known problems (limits): //// +//// Inserts one wait state on all transfers. //// +//// Note affected signals and the way they are affected. //// +//// //// +//// To Do: //// +//// Nothing. //// +//// //// +//// Author(s): //// +//// - gorban@opencores.org //// +//// - Jacob Gorban //// +//// - Igor Mohor (igorm@opencores.org) //// +//// //// +//// Created: 2001/05/12 //// +//// Last Updated: 2001/05/17 //// +//// (See log for the revision history) //// +//// //// +//// //// +////////////////////////////////////////////////////////////////////// +//// //// +//// Copyright (C) 2000, 2001 Authors //// +//// //// +//// This source file may be used and distributed without //// +//// restriction provided that this copyright statement is not //// +//// removed from the file and that any derivative work contains //// +//// the original copyright notice and the associated disclaimer. //// +//// //// +//// This source file is free software; you can redistribute it //// +//// and/or modify it under the terms of the GNU Lesser General //// +//// Public License as published by the Free Software Foundation; //// +//// either version 2.1 of the License, or (at your option) any //// +//// later version. //// +//// //// +//// This source is distributed in the hope that it will be //// +//// useful, but WITHOUT ANY WARRANTY; without even the implied //// +//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR //// +//// PURPOSE. See the GNU Lesser General Public License for more //// +//// details. //// +//// //// +//// You should have received a copy of the GNU Lesser General //// +//// Public License along with this source; if not, download it //// +//// from http://www.opencores.org/lgpl.shtml //// +//// //// +////////////////////////////////////////////////////////////////////// +// +// CVS Revision History +// +// $Log: not supported by cvs2svn $ +// Revision 1.16 2002/07/29 21:16:18 gorban +// The uart_defines.v file is included again in sources. +// +// Revision 1.15 2002/07/22 23:02:23 gorban +// Bug Fixes: +// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed. +// Problem reported by Kenny.Tung. +// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers. +// +// Improvements: +// * Made FIFO's as general inferrable memory where possible. +// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx). +// This saves about 1/3 of the Slice count and reduces P&R and synthesis times. +// +// * Added optional baudrate output (baud_o). +// This is identical to BAUDOUT* signal on 16550 chip. +// It outputs 16xbit_clock_rate - the divided clock. +// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use. +// +// Revision 1.12 2001/12/19 08:03:34 mohor +// Warnings cleared. +// +// Revision 1.11 2001/12/06 14:51:04 gorban +// Bug in LSR[0] is fixed. +// All WISHBONE signals are now sampled, so another wait-state is introduced on all transfers. +// +// Revision 1.10 2001/12/03 21:44:29 gorban +// Updated specification documentation. +// Added full 32-bit data bus interface, now as default. +// Address is 5-bit wide in 32-bit data bus mode. +// Added wb_sel_i input to the core. It's used in the 32-bit mode. +// Added debug interface with two 32-bit read-only registers in 32-bit mode. +// Bits 5 and 6 of LSR are now only cleared on TX FIFO write. +// My small test bench is modified to work with 32-bit mode. +// +// Revision 1.9 2001/10/20 09:58:40 gorban +// Small synopsis fixes +// +// Revision 1.8 2001/08/24 21:01:12 mohor +// Things connected to parity changed. +// Clock devider changed. +// +// Revision 1.7 2001/08/23 16:05:05 mohor +// Stop bit bug fixed. +// Parity bug fixed. +// WISHBONE read cycle bug fixed, +// OE indicator (Overrun Error) bug fixed. +// PE indicator (Parity Error) bug fixed. +// Register read bug fixed. +// +// Revision 1.4 2001/05/31 20:08:01 gorban +// FIFO changes and other corrections. +// +// Revision 1.3 2001/05/21 19:12:01 gorban +// Corrected some Linter messages. +// +// Revision 1.2 2001/05/17 18:34:18 gorban +// First 'stable' release. Should be sythesizable now. Also added new header. +// +// Revision 1.0 2001-05-17 21:27:13+02 jacob +// Initial revision +// +// + +// UART core WISHBONE interface +// +// Author: Jacob Gorban (jacob.gorban@flextronicssemi.com) +// Company: Flextronics Semiconductor +// + +`include "uart_defines.v" + +module uart_wb (clk, wb_rst_i, + wb_we_i, wb_stb_i, wb_cyc_i, wb_ack_o, wb_adr_i, + wb_adr_int, wb_dat_i, wb_dat_o, wb_dat8_i, wb_dat8_o, wb_dat32_o, wb_sel_i, + we_o, re_o // Write and read enable output for the core +); + +input clk; + +// WISHBONE interface +input wb_rst_i; +input wb_we_i; +input wb_stb_i; +input wb_cyc_i; +input [3:0] wb_sel_i; +input [2:0] wb_adr_i; //WISHBONE address line + +input [7:0] wb_dat_i; //input WISHBONE bus +output [7:0] wb_dat_o; +reg [7:0] wb_dat_o; +wire [7:0] wb_dat_i; +reg [7:0] wb_dat_is; + +output [2:0] wb_adr_int; // internal signal for address bus +input [7:0] wb_dat8_o; // internal 8 bit output to be put into wb_dat_o +output [7:0] wb_dat8_i; +input [31:0] wb_dat32_o; // 32 bit data output (for debug interface) +output wb_ack_o; +output we_o; +output re_o; + +wire we_o; +reg wb_ack_o; +reg [7:0] wb_dat8_i; +wire [7:0] wb_dat8_o; +wire [2:0] wb_adr_int; // internal signal for address bus +reg [2:0] wb_adr_is; +reg wb_we_is; +reg wb_cyc_is; +reg wb_stb_is; +wire [3:0] wb_sel_i; +reg wre ;// timing control signal for write or read enable + +// wb_ack_o FSM +reg [1:0] wbstate; +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) begin + wb_ack_o <= 1'b0; + wbstate <= 0; + wre <= 1'b1; + end else + case (wbstate) + 0: begin + if (wb_stb_is & wb_cyc_is) begin + wre <= 0; + wbstate <= 1; + wb_ack_o <= 1; + end else begin + wre <= 1; + wb_ack_o <= 0; + end + end + 1: begin + wb_ack_o <= 0; + wbstate <= 2; + wre <= 0; + end + 2: begin + wb_ack_o <= 0; + wbstate <= 3; + wre <= 0; + end + 3: begin + wb_ack_o <= 0; + wbstate <= 0; + wre <= 1; + end + endcase + +assign we_o = wb_we_is & wb_stb_is & wb_cyc_is & wre ; //WE for registers +assign re_o = ~wb_we_is & wb_stb_is & wb_cyc_is & wre ; //RE for registers + +// Sample input signals +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) begin + wb_adr_is <= 0; + wb_we_is <= 0; + wb_cyc_is <= 0; + wb_stb_is <= 0; + wb_dat_is <= 0; + end else begin + wb_adr_is <= wb_adr_i; + wb_we_is <= wb_we_i; + wb_cyc_is <= wb_cyc_i; + wb_stb_is <= wb_stb_i; + wb_dat_is <= wb_dat_i; + end + +always @(posedge clk or posedge wb_rst_i) + if (wb_rst_i) + wb_dat_o <= 0; + else + wb_dat_o <= wb_dat8_o; + +always @(wb_dat_is) + wb_dat8_i = wb_dat_is; + +assign wb_adr_int = wb_adr_is; + + +endmodule + + + + + + + + + +