tests/simple/omsp_dbg_uart.v

   1
   2 module  omsp_dbg_uart (dbg_clk, dbg_rst, mem_burst, cmd_valid);
   3
   4 input dbg_clk;
   5 input dbg_rst;
   6 input mem_burst;
   7 output cmd_valid;
   8
   9 reg [2:0] uart_state;
  10 reg [2:0] uart_state_nxt;
  11
  12 wire xfer_done;
  13
  14 parameter  RX_SYNC  = 3'h0;
  15 parameter  RX_CMD   = 3'h1;
  16 parameter  RX_DATA = 3'h2;
  17
  18 always @(uart_state or mem_burst)
  19   case (uart_state)
  20     RX_SYNC  : uart_state_nxt =  RX_CMD;
  21     RX_CMD   : uart_state_nxt =  mem_burst ? RX_DATA : RX_SYNC;
  22     RX_DATA : uart_state_nxt =  RX_SYNC;
  23     default  : uart_state_nxt =  RX_CMD;
  24   endcase
  25
  26 always @(posedge dbg_clk or posedge dbg_rst)
  27   if (dbg_rst) uart_state <= RX_SYNC;
  28   else if (xfer_done | mem_burst) uart_state <= uart_state_nxt;
  29
  30 assign cmd_valid = (uart_state==RX_CMD) & xfer_done;
  31 assign xfer_done = uart_state!=RX_SYNC;
  32
  33 endmodule
  34