techlibs/efinix/arith_map.v

   1 /*
   2  *  yosys -- Yosys Open SYnthesis Suite
   3  *
   4  *  Copyright (C) 2018  Miodrag Milanovic <miodrag@symbioticeda.com>
   5  *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
   6  *
   7  *  Permission to use, copy, modify, and/or distribute this software for any
   8  *  purpose with or without fee is hereby granted, provided that the above
   9  *  copyright notice and this permission notice appear in all copies.
  10  *
  11  *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12  *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14  *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17  *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  *
  19  */
  20
  21 (* techmap_celltype = "$alu" *)
  22 module _80_efinix_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
  36     wire CIx;
  37     wire [Y_WIDTH-1:0] COx;
  38
  39         wire _TECHMAP_FAIL_ = Y_WIDTH <= 2;
  40
  41         wire [Y_WIDTH-1:0] A_buf, B_buf;
  42         \$pos #(.A_SIGNED(A_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf));
  43         \$pos #(.A_SIGNED(B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf));
  44
  45         wire [Y_WIDTH-1:0] AA = A_buf;
  46         wire [Y_WIDTH-1:0] BB = BI ? ~B_buf : B_buf;
  47         wire [Y_WIDTH-1:0] C = { COx, CIx };
  48
  49     EFX_ADD #(.I0_POLARITY(1'b1),.I1_POLARITY(1'b1))
  50     adder_cin  (
  51         .I0(CI),
  52         .I1(1'b1),
  53         .CI(1'b0),
  54         .CO(CIx)
  55         );
  56
  57         genvar i;
  58         generate for (i = 0; i < Y_WIDTH; i = i + 1) begin: slice
  59                 EFX_ADD #(.I0_POLARITY(1'b1),.I1_POLARITY(1'b1))
  60                 adder_i (
  61                         .I0(AA[i]),
  62                         .I1(BB[i]),
  63                         .CI(C[i]),
  64                         .O(Y[i]),
  65                         .CO(COx[i])
  66                 );
  67                 EFX_ADD #(.I0_POLARITY(1'b1),.I1_POLARITY(1'b1))
  68                 adder_cout  (
  69                         .I0(1'b0),
  70                         .I1(1'b0),
  71                         .CI(COx[i]),
  72                         .O(CO[i])
  73                 );
  74           end: slice
  75         endgenerate
  76
  77    /* End implementation */
  78    assign X = AA ^ BB;
  79 endmodule