techlibs/common/mul2dsp.v

   1 // From Eddie Hung
   2 // extracted from: https://github.com/eddiehung/vtr-with-yosys/blob/vtr7-with-yosys/vtr_flow/misc/yosys_models.v#L220
   3 // revised by Andre DeHon
   4 // further revised by David Shah
   5 `ifndef DSP_A_MAXWIDTH
   6 `define DSP_A_MAXWIDTH 18
   7 `endif
   8 `ifndef DSP_A_MAXWIDTH
   9 `define DSP_B_MAXWIDTH 25
  10 `endif
  11
  12 `ifndef ADDER_MINWIDTH
  13 `define ADDER_MINWIDTH AAA
  14 `endif
  15
  16 `ifndef DSP_NAME
  17 `define DSP_NAME M18x25
  18 `endif
  19
  20 `define MAX(a,b) (a > b ? a : b)
  21 `define MIN(a,b) (a < b ? a : b)
  22
  23 (* techmap_celltype = "$mul" *)
  24 module \$mul (A, B, Y);
  25         parameter A_SIGNED = 0;
  26         parameter B_SIGNED = 0;
  27         parameter A_WIDTH = 1;
  28         parameter B_WIDTH = 1;
  29         parameter Y_WIDTH = 1;
  30
  31         input [A_WIDTH-1:0] A;
  32         input [B_WIDTH-1:0] B;
  33         output [Y_WIDTH-1:0] Y;
  34
  35         generate
  36                 if (B_WIDTH < A_WIDTH)
  37                         \$__mul_gen #(
  38                                 .A_SIGNED(A_SIGNED),
  39                                 .B_SIGNED(B_SIGNED),
  40                                 .A_WIDTH(A_WIDTH),
  41                                 .B_WIDTH(B_WIDTH),
  42                                 .Y_WIDTH(Y_WIDTH)
  43                         ) mul_slice (
  44                                 .A(A),
  45                                 .B(B),
  46                                 .Y(Y)
  47                         );
  48                 else
  49                         \$__mul_gen #(
  50                                 .A_SIGNED(B_SIGNED),
  51                                 .B_SIGNED(A_SIGNED),
  52                                 .A_WIDTH(B_WIDTH),
  53                                 .B_WIDTH(A_WIDTH),
  54                                 .Y_WIDTH(Y_WIDTH)
  55                         ) mul_slice (
  56                                 .A(B),
  57                                 .B(A),
  58                                 .Y(Y)
  59                         );
  60         endgenerate
  61 endmodule
  62
  63 module \$__mul_gen (A, B, Y);
  64         parameter A_SIGNED = 0;
  65         parameter B_SIGNED = 0;
  66         parameter A_WIDTH = 1;
  67         parameter B_WIDTH = 1;
  68         parameter Y_WIDTH = 1;
  69
  70         input [A_WIDTH-1:0] A;
  71         input [B_WIDTH-1:0] B;
  72         output [Y_WIDTH-1:0] Y;
  73
  74         wire [1023:0] _TECHMAP_DO_ = "proc; clean";
  75
  76         genvar i;
  77         generate
  78                 if (A_WIDTH > `DSP_A_MAXWIDTH) begin
  79                         localparam n_floored = A_WIDTH/`DSP_A_MAXWIDTH;
  80                         localparam n = n_floored + (n_floored*`DSP_A_MAXWIDTH < A_WIDTH ? 1 : 0);
  81                         wire [`DSP_A_MAXWIDTH+B_WIDTH-1:0] partial [n-1:1];
  82                         wire [Y_WIDTH-1:0] partial_sum [n-2:0];
  83
  84                         \$__mul_gen #(
  85                                 .A_SIGNED(A_SIGNED),
  86                                 .B_SIGNED(B_SIGNED),
  87                                 .A_WIDTH(`DSP_A_MAXWIDTH),
  88                                 .B_WIDTH(B_WIDTH),
  89                                 .Y_WIDTH(B_WIDTH+`DSP_A_MAXWIDTH)
  90                         ) mul_slice_first (
  91                                 .A(A[`DSP_A_MAXWIDTH-1:0]),
  92                                 .B(B),
  93                                 .Y(partial_sum[0][B_WIDTH+`DSP_A_MAXWIDTH-1:0])
  94                         );
  95                         assign partial_sum[0][Y_WIDTH-1:B_WIDTH+`DSP_A_MAXWIDTH]=0;
  96
  97                         for (i = 1; i < n-1; i=i+1) begin:slice
  98                                 \$__mul_gen #(
  99                                         .A_SIGNED(A_SIGNED),
 100                                         .B_SIGNED(B_SIGNED),
 101                                         .A_WIDTH(`DSP_A_MAXWIDTH),
 102                                         .B_WIDTH(B_WIDTH),
 103                                         .Y_WIDTH(B_WIDTH+`DSP_A_MAXWIDTH)
 104                                 ) mul_slice (
 105                                         .A(A[(i+1)*`DSP_A_MAXWIDTH-1:i*`DSP_A_MAXWIDTH]),
 106                                         .B(B),
 107                                         .Y(partial[i][B_WIDTH+`DSP_A_MAXWIDTH-1:0])
 108                                 );
 109                                 //assign partial_sum[i] = (partial[i] << i*`DSP_A_MAXWIDTH) + partial_sum[i-1];
 110                                 assign partial_sum[i] = {
 111                                         partial[i][B_WIDTH+`DSP_A_MAXWIDTH-1:0]
 112                                         + partial_sum[i-1][Y_WIDTH-1:(i*`DSP_A_MAXWIDTH)],
 113                                         partial_sum[i-1][(i*`DSP_A_MAXWIDTH)-1:0]
 114                                 };
 115                         end
 116
 117                         \$__mul_gen #(
 118                                 .A_SIGNED(A_SIGNED),
 119                                 .B_SIGNED(B_SIGNED),
 120                                 .A_WIDTH(A_WIDTH-(n-1)*`DSP_A_MAXWIDTH),
 121                                 .B_WIDTH(B_WIDTH),
 122                                 .Y_WIDTH(A_WIDTH-(n-1)*`DSP_A_MAXWIDTH+B_WIDTH),
 123                         ) mul_slice_last (
 124                                 .A(A[A_WIDTH-1:(n-1)*`DSP_A_MAXWIDTH]),
 125                                 .B(B),
 126                                 .Y(partial[n-1][A_WIDTH-(n-1)*`DSP_A_MAXWIDTH+B_WIDTH-1:0])
 127                         );
 128                         //assign Y = (partial[n-1] << (n-1)*`DSP_A_MAXWIDTH) + partial_sum[n-2];
 129                         assign Y = {
 130                                 partial[n-1][A_WIDTH-(n-1)*`DSP_A_MAXWIDTH+B_WIDTH:0]
 131                                 + partial_sum[n-2][Y_WIDTH-1:((n-1)*`DSP_A_MAXWIDTH)],
 132                                 partial_sum[n-2][((n-1)*`DSP_A_MAXWIDTH)-1:0]
 133                         };
 134                 end
 135                 else if (B_WIDTH > `DSP_B_MAXWIDTH) begin
 136                         localparam n_floored = B_WIDTH/`DSP_B_MAXWIDTH;
 137                         localparam n = n_floored + (n_floored*`DSP_B_MAXWIDTH < B_WIDTH ? 1 : 0);
 138                         wire [A_WIDTH+`DSP_B_MAXWIDTH-1:0] partial [n-1:1];
 139                         wire [Y_WIDTH-1:0] partial_sum [n-2:0];
 140
 141                         \$__mul_gen #(
 142                                 .A_SIGNED(A_SIGNED),
 143                                 .B_SIGNED(B_SIGNED),
 144                                 .A_WIDTH(A_WIDTH),
 145                                 .B_WIDTH(`DSP_B_MAXWIDTH),
 146                                 .Y_WIDTH(A_WIDTH+`DSP_B_MAXWIDTH)
 147                         ) mul_first (
 148                                 .A(A),
 149                                 .B(B[`DSP_B_MAXWIDTH-1:0]),
 150                                 .Y(partial_sum[0][A_WIDTH+`DSP_B_MAXWIDTH-1:0])
 151                         );
 152                         assign partial_sum[0][Y_WIDTH-1:A_WIDTH+`DSP_B_MAXWIDTH]=0;
 153
 154                         for (i = 1; i < n-1; i=i+1) begin:slice
 155                                 \$__mul_gen #(
 156                                         .A_SIGNED(A_SIGNED),
 157                                         .B_SIGNED(B_SIGNED),
 158                                         .A_WIDTH(A_WIDTH),
 159                                         .B_WIDTH(`DSP_B_MAXWIDTH),
 160                                                 .Y_WIDTH(A_WIDTH+`DSP_B_MAXWIDTH)
 161                                 ) mul (
 162                                         .A(A),
 163                                         .B(B[(i+1)*`DSP_B_MAXWIDTH-1:i*`DSP_B_MAXWIDTH]),
 164                                         .Y(partial[i][A_WIDTH+`DSP_B_MAXWIDTH-1:0])
 165                                 );
 166                                 //assign partial_sum[i] = (partial[i] << i*`DSP_B_MAXWIDTH) + partial_sum[i-1];
 167                                 // was:
 168                                 //assign partial_sum[i] = {
 169                                 //  partial[i][A_WIDTH+`DSP_B_MAXWIDTH-1:`DSP_B_MAXWIDTH],
 170                                 //      partial[i][`DSP_B_MAXWIDTH-1:0] + partial_sum[i-1][A_WIDTH+(i*`DSP_B_MAXWIDTH)-1:A_WIDTH+((i-1)*`DSP_B_MAXWIDTH)],
 171                                 //      partial_sum[i-1][A_WIDTH+((i-1)*`DSP_B_MAXWIDTH):0]
 172                                 assign partial_sum[i] = {
 173                                         partial[i][A_WIDTH+`DSP_B_MAXWIDTH-1:0]
 174                                         + partial_sum[i-1][Y_WIDTH-1:(i*`DSP_B_MAXWIDTH)],
 175                                         partial_sum[i-1][(i*`DSP_B_MAXWIDTH)-1:0]
 176                                 };
 177                         end
 178
 179                         \$__mul_gen #(
 180                                 .A_SIGNED(A_SIGNED),
 181                                 .B_SIGNED(B_SIGNED),
 182                                 .A_WIDTH(A_WIDTH),
 183                                 .B_WIDTH(B_WIDTH-(n-1)*`DSP_B_MAXWIDTH),
 184                                 .Y_WIDTH(A_WIDTH+B_WIDTH-(n-1)*`DSP_B_MAXWIDTH)
 185                         ) mul_last (
 186                                 .A(A),
 187                                 .B(B[B_WIDTH-1:(n-1)*`DSP_B_MAXWIDTH]),
 188                                 .Y(partial[n-1][A_WIDTH+B_WIDTH-(n-1)*`DSP_B_MAXWIDTH-1:0])
 189                         );
 190                         // AMD: this came comment out -- looks closer to right answer
 191                         //assign Y = (partial[n-1] << (n-1)*`DSP_B_MAXWIDTH) + partial_sum[n-2];
 192                         // was (looks broken)
 193                         //assign Y = {
 194                         //      partial[n-1][A_WIDTH+`DSP_B_MAXWIDTH-1:`DSP_B_MAXWIDTH],
 195                         //      partial[n-1][`DSP_B_MAXWIDTH-1:0] + partial_sum[n-2][A_WIDTH+((n-1)*`DSP_B_MAXWIDTH)-1:A_WIDTH+((n-2)*`DSP_B_MAXWIDTH)],
 196                         //      partial_sum[n-2][A_WIDTH+((n-2)*`DSP_B_MAXWIDTH):0]
 197                         assign Y = {
 198                                 partial[n-1][A_WIDTH+B_WIDTH-(n-1)*`DSP_B_MAXWIDTH-1:0]
 199                                 + partial_sum[n-2][Y_WIDTH-1:((n-1)*`DSP_B_MAXWIDTH)],
 200                                 partial_sum[n-2][((n-1)*`DSP_B_MAXWIDTH)-1:0]
 201                         };
 202                 end
 203                 else begin
 204                         wire [A_WIDTH+B_WIDTH-1:0] out;
 205                         wire [(`DSP_A_MAXWIDTH+`DSP_B_MAXWIDTH)-(A_WIDTH+B_WIDTH)-1:0] dummy;
 206                         wire Asign, Bsign;
 207                         assign Asign = (A_SIGNED ? A[A_WIDTH-1] : 1'b0);
 208                         assign Bsign = (B_SIGNED ? B[B_WIDTH-1] : 1'b0);
 209                         `DSP_NAME _TECHMAP_REPLACE_ (
 210                                 .A({ {{`DSP_A_MAXWIDTH-A_WIDTH}{Asign}}, A }),
 211                                 .B({ {{`DSP_B_MAXWIDTH-B_WIDTH}{Bsign}}, B }),
 212                                 .OUT({dummy, out})
 213                         );
 214                         if (Y_WIDTH < A_WIDTH+B_WIDTH)
 215                                 assign Y = out[Y_WIDTH-1:0];
 216                         else begin
 217                                 wire Ysign = (A_SIGNED || B_SIGNED ? out[A_WIDTH+B_WIDTH-1] : 1'b0);
 218                                 assign Y = { {{Y_WIDTH-(A_WIDTH+B_WIDTH)}{Ysign}}, out[A_WIDTH+B_WIDTH-1:0] };
 219                         end
 220                 end
 221         endgenerate
 222 endmodule
 223
 224