techlibs/achronix/speedster22i/cells_arith.v

   1 /*
   2  *  yosys -- Yosys Open SYnthesis Suite
   3  *
   4  *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
   5  *
   6  *  Permission to use, copy, modify, and/or distribute this software for any
   7  *  purpose with or without fee is hereby granted, provided that the above
   8  *  copyright notice and this permission notice appear in all copies.
   9  *
  10  *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  *
  18  */
  19
  20 // NOTE: This is still WIP.
  21 (* techmap_celltype = "$alu" *)
  22 module _80_altera_max10_alu (A, B, CI, BI, X, Y, CO);
  23    parameter A_SIGNED = 0;
  24    parameter B_SIGNED = 0;
  25    parameter A_WIDTH  = 1;
  26    parameter B_WIDTH  = 1;
  27    parameter Y_WIDTH  = 1;
  28
  29         input [A_WIDTH-1:0] A;
  30         input [B_WIDTH-1:0] B;
  31         output [Y_WIDTH-1:0] X, Y;
  32
  33         input CI, BI;
  34         //output [Y_WIDTH-1:0] CO;
  35         output                 CO;
  36
  37         wire _TECHMAP_FAIL_ = Y_WIDTH <= 4;
  38
  39         wire [Y_WIDTH-1:0] A_buf, B_buf;
  40         \$pos #(.A_SIGNED(A_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf));
  41         \$pos #(.A_SIGNED(B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf));
  42
  43         wire [Y_WIDTH-1:0] AA = A_buf;
  44         wire [Y_WIDTH-1:0] BB = BI ? ~B_buf : B_buf;
  45         //wire [Y_WIDTH:0] C = {CO, CI};
  46         wire [Y_WIDTH+1:0] COx;
  47         wire [Y_WIDTH+1:0] C = {COx, CI};
  48
  49         /* Start implementation */
  50         (* keep *) fiftyfivenm_lcell_comb #(.lut_mask(16'b0000_0000_1010_1010), .sum_lutc_input("cin")) carry_start (.cout(COx[0]), .dataa(C[0]), .datab(1'b1), .datac(1'b1), .datad(1'b1));
  51
  52         genvar i;
  53         generate for (i = 0; i < Y_WIDTH; i = i + 1) begin: slice
  54           if(i==Y_WIDTH-1) begin
  55             (* keep *) fiftyfivenm_lcell_comb #(.lut_mask(16'b1111_0000_1110_0000), .sum_lutc_input("cin")) carry_end (.combout(COx[Y_WIDTH]), .dataa(1'b1), .datab(1'b1), .datac(1'b1), .datad(1'b1), .cin(C[Y_WIDTH]));
  56             assign CO = COx[Y_WIDTH];
  57           end
  58           else
  59             fiftyfivenm_lcell_comb #(.lut_mask(16'b1001_0110_1110_1000), .sum_lutc_input("cin")) arith_cell (.combout(Y[i]), .cout(COx[i+1]), .dataa(AA[i]), .datab(BB[i]), .datac(1'b1), .datad(1'b1), .cin(C[i+1]));
  60           end: slice
  61         endgenerate
  62         /* End implementation */
  63         assign X = AA ^ BB;
  64
  65 endmodule