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// From Eddie Hung
// extracted from: https://github.com/eddiehung/vtr-with-yosys/blob/vtr7-with-yosys/vtr_flow/misc/yosys_models.v#L220
// revised by Andre DeHon
// further revised by David Shah
`ifndef DSP_A_MAXWIDTH
`define DSP_A_MAXWIDTH 18
`endif
`ifndef DSP_A_MAXWIDTH
`define DSP_B_MAXWIDTH 25
`endif
`ifndef ADDER_MINWIDTH
`define ADDER_MINWIDTH AAA
`endif
`ifndef DSP_NAME
`define DSP_NAME M18x25
`endif
`define MAX(a,b) (a > b ? a : b)
`define MIN(a,b) (a < b ? a : b)
(* techmap_celltype = "$mul" *)
module \$mul (A, B, Y);
parameter A_SIGNED = 0;
parameter B_SIGNED = 0;
parameter A_WIDTH = 1;
parameter B_WIDTH = 1;
parameter Y_WIDTH = 1;
input [A_WIDTH-1:0] A;
input [B_WIDTH-1:0] B;
output [Y_WIDTH-1:0] Y;
wire [1023:0] _TECHMAP_DO_ = "proc; clean";
generate
if (A_WIDTH<B_WIDTH) begin
generate
\$__mul_gen #(
.A_SIGNED(A_SIGNED),
.B_SIGNED(B_SIGNED),
.A_WIDTH(A_WIDTH),
.B_WIDTH(B_WIDTH),
.Y_WIDTH(Y_WIDTH)
) mul_slice (
.A(A),
.B(B),
.Y(Y[Y_WIDTH-1:0])
);
endgenerate
end
else begin
generate
\$__mul_gen #(
.A_SIGNED(B_SIGNED),
.B_SIGNED(A_SIGNED),
.A_WIDTH(B_WIDTH),
.B_WIDTH(A_WIDTH),
.Y_WIDTH(Y_WIDTH)
) mul_slice (
.A(B),
.B(A),
.Y(Y[Y_WIDTH-1:0])
);
endgenerate
end
endgenerate
endmodule
module \$__mul_gen (A, B, Y);
parameter A_SIGNED = 0;
parameter B_SIGNED = 0;
parameter A_WIDTH = 1;
parameter B_WIDTH = 1;
parameter Y_WIDTH = 1;
input [A_WIDTH-1:0] A;
input [B_WIDTH-1:0] B;
output [Y_WIDTH-1:0] Y;
wire [1023:0] _TECHMAP_DO_ = "proc; clean";
generate
if (A_WIDTH > `DSP_A_MAXWIDTH) begin
localparam n_floored = A_WIDTH/`DSP_A_MAXWIDTH;
localparam n = n_floored + (n_floored*`DSP_A_MAXWIDTH < A_WIDTH ? 1 : 0);
wire [`DSP_A_MAXWIDTH+B_WIDTH-1:0] partial [n-1:1];
wire [Y_WIDTH-1:0] partial_sum [n-2:0];
\$__mul_gen #(
.A_SIGNED(A_SIGNED),
.B_SIGNED(B_SIGNED),
.A_WIDTH(`DSP_A_MAXWIDTH),
.B_WIDTH(B_WIDTH),
.Y_WIDTH(B_WIDTH+`DSP_A_MAXWIDTH)
) mul_slice_first (
.A(A[`DSP_A_MAXWIDTH-1:0]),
.B(B),
.Y(partial_sum[0][B_WIDTH+`DSP_A_MAXWIDTH-1:0])
);
assign partial_sum[0][Y_WIDTH-1:B_WIDTH+`DSP_A_MAXWIDTH]=0;
genvar i;
generate
for (i = 1; i < n-1; i=i+1) begin:slice
\$__mul_gen #(
.A_SIGNED(A_SIGNED),
.B_SIGNED(B_SIGNED),
.A_WIDTH(`DSP_A_MAXWIDTH),
.B_WIDTH(B_WIDTH),
.Y_WIDTH(B_WIDTH+`DSP_A_MAXWIDTH)
) mul_slice (
.A(A[(i+1)*`DSP_A_MAXWIDTH-1:i*`DSP_A_MAXWIDTH]),
.B(B),
.Y(partial[i][B_WIDTH+`DSP_A_MAXWIDTH-1:0])
);
//assign partial_sum[i] = (partial[i] << i*`DSP_A_MAXWIDTH) + partial_sum[i-1];
assign partial_sum[i] = {
partial[i][B_WIDTH+`DSP_A_MAXWIDTH-1:0]
+ partial_sum[i-1][Y_WIDTH-1:(i*`DSP_A_MAXWIDTH)],
partial_sum[i-1][(i*`DSP_A_MAXWIDTH)-1:0]
};
end
endgenerate
\$__mul_gen #(
.A_SIGNED(A_SIGNED),
.B_SIGNED(B_SIGNED),
.A_WIDTH(A_WIDTH-(n-1)*`DSP_A_MAXWIDTH),
.B_WIDTH(B_WIDTH),
.Y_WIDTH(A_WIDTH-(n-1)*`DSP_A_MAXWIDTH+B_WIDTH),
) mul_slice_last (
.A(A[A_WIDTH-1:(n-1)*`DSP_A_MAXWIDTH]),
.B(B),
.Y(partial[n-1][A_WIDTH-(n-1)*`DSP_A_MAXWIDTH+B_WIDTH-1:0])
);
//assign Y = (partial[n-1] << (n-1)*`DSP_A_MAXWIDTH) + partial_sum[n-2];
assign Y = {
partial[n-1][A_WIDTH-(n-1)*`DSP_A_MAXWIDTH+B_WIDTH:0]
+ partial_sum[n-2][Y_WIDTH-1:((n-1)*`DSP_A_MAXWIDTH)],
partial_sum[n-2][((n-1)*`DSP_A_MAXWIDTH)-1:0]
};
end
else if (B_WIDTH > `DSP_B_MAXWIDTH) begin
localparam n_floored = B_WIDTH/`DSP_B_MAXWIDTH;
localparam n = n_floored + (n_floored*`DSP_B_MAXWIDTH < B_WIDTH ? 1 : 0);
wire [A_WIDTH+`DSP_B_MAXWIDTH-1:0] partial [n-1:1];
wire [Y_WIDTH-1:0] partial_sum [n-2:0];
\$__mul_gen #(
.A_SIGNED(A_SIGNED),
.B_SIGNED(B_SIGNED),
.A_WIDTH(A_WIDTH),
.B_WIDTH(`DSP_B_MAXWIDTH),
.Y_WIDTH(A_WIDTH+`DSP_B_MAXWIDTH)
) mul_first (
.A(A),
.B(B[`DSP_B_MAXWIDTH-1:0]),
.Y(partial_sum[0][A_WIDTH+`DSP_B_MAXWIDTH-1:0])
);
assign partial_sum[0][Y_WIDTH-1:A_WIDTH+`DSP_B_MAXWIDTH]=0;
genvar i;
generate
for (i = 1; i < n-1; i=i+1) begin:slice
\$__mul_gen #(
.A_SIGNED(A_SIGNED),
.B_SIGNED(B_SIGNED),
.A_WIDTH(A_WIDTH),
.B_WIDTH(`DSP_B_MAXWIDTH),
.Y_WIDTH(A_WIDTH+`DSP_B_MAXWIDTH)
) mul (
.A(A),
.B(B[(i+1)*`DSP_B_MAXWIDTH-1:i*`DSP_B_MAXWIDTH]),
.Y(partial[i][A_WIDTH+`DSP_B_MAXWIDTH-1:0])
);
//assign partial_sum[i] = (partial[i] << i*`DSP_B_MAXWIDTH) + partial_sum[i-1];
// was:
//assign partial_sum[i] = {
// partial[i][A_WIDTH+`DSP_B_MAXWIDTH-1:`DSP_B_MAXWIDTH],
// 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)],
// partial_sum[i-1][A_WIDTH+((i-1)*`DSP_B_MAXWIDTH):0]
assign partial_sum[i] = {
partial[i][A_WIDTH+`DSP_B_MAXWIDTH-1:0]
+ partial_sum[i-1][Y_WIDTH-1:(i*`DSP_B_MAXWIDTH)],
partial_sum[i-1][(i*`DSP_B_MAXWIDTH)-1:0]
};
end
endgenerate
\$__mul_gen #(
.A_SIGNED(A_SIGNED),
.B_SIGNED(B_SIGNED),
.A_WIDTH(A_WIDTH),
.B_WIDTH(B_WIDTH-(n-1)*`DSP_B_MAXWIDTH),
.Y_WIDTH(A_WIDTH+B_WIDTH-(n-1)*`DSP_B_MAXWIDTH)
) mul_last (
.A(A),
.B(B[B_WIDTH-1:(n-1)*`DSP_B_MAXWIDTH]),
.Y(partial[n-1][A_WIDTH+B_WIDTH-(n-1)*`DSP_B_MAXWIDTH-1:0])
);
// AMD: this came comment out -- looks closer to right answer
//assign Y = (partial[n-1] << (n-1)*`DSP_B_MAXWIDTH) + partial_sum[n-2];
// was (looks broken)
//assign Y = {
// partial[n-1][A_WIDTH+`DSP_B_MAXWIDTH-1:`DSP_B_MAXWIDTH],
// 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)],
// partial_sum[n-2][A_WIDTH+((n-2)*`DSP_B_MAXWIDTH):0]
assign Y = {
partial[n-1][A_WIDTH+B_WIDTH-(n-1)*`DSP_B_MAXWIDTH-1:0]
+ partial_sum[n-2][Y_WIDTH-1:((n-1)*`DSP_B_MAXWIDTH)],
partial_sum[n-2][((n-1)*`DSP_B_MAXWIDTH)-1:0]
};
end
else begin
wire [A_WIDTH+B_WIDTH-1:0] out;
wire [(`DSP_A_MAXWIDTH+`DSP_B_MAXWIDTH)-(A_WIDTH+B_WIDTH)-1:0] dummy;
wire Asign, Bsign;
assign Asign = (A_SIGNED ? A[A_WIDTH-1] : 1'b0);
assign Bsign = (B_SIGNED ? B[B_WIDTH-1] : 1'b0);
`DSP_NAME _TECHMAP_REPLACE_ (
.A({ {{`DSP_A_MAXWIDTH-A_WIDTH}{Asign}}, A }),
.B({ {{`DSP_B_MAXWIDTH-B_WIDTH}{Bsign}}, B }),
.OUT({dummy, out})
);
if (Y_WIDTH < A_WIDTH+B_WIDTH)
assign Y = out[Y_WIDTH-1:0];
else begin
wire Ysign = (A_SIGNED || B_SIGNED ? out[A_WIDTH+BWIDTH-1] : 1'b0);
assign Y = { {{Y_WIDTH-(A_WIDTH+B_WIDTH)}{Ysign}}, out[A_WIDTH+B_WIDTH-1:0] };
end
end
endgenerate
endmodule
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