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Fix B_WIDTH > DSP_B_MAXWIDTH case

This commit is contained in:
Eddie Hung 2019-08-01 10:01:43 -07:00
parent c54a39069d
commit 7e86c8bcfb
1 changed files with 14 additions and 32 deletions
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46
techlibs/common/mul2dsp.v
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@ -67,22 +67,6 @@ module \$mul (A, B, Y);
.B(A),
.Y(Y)
);
else if (A_SIGNED && (A_WIDTH > `DSP_A_MAXWIDTH || B_WIDTH > `DSP_B_MAXWIDTH)) begin
wire _;
\$__mul #(
.A_SIGNED(A_SIGNED),
.B_SIGNED(B_SIGNED),
.A_WIDTH(A_WIDTH),
.B_WIDTH(B_WIDTH),
.Y_WIDTH(Y_WIDTH)
) _TECHMAP_REPLACE_ (
.A(A),
.B(B),
.Y({_,Y[Y_WIDTH-2:0]})
);
// For non-zero results, recompute sign bit
assign Y[Y_WIDTH-1] = (|Y[Y_WIDTH-2:0]) & (A[A_WIDTH-1] ^ B[B_WIDTH-1]);
end
else
\$__mul #(
.A_SIGNED(A_SIGNED),
@ -171,14 +155,15 @@ module \$__mul (A, B, Y);
assign partial_sum[i] = (partial[i] << i*(`DSP_A_MAXWIDTH-sign_headroom)) + partial_sum[i-1];
end
localparam last_A_WIDTH = A_WIDTH-(n-1)*(`DSP_A_MAXWIDTH-sign_headroom);
\$__mul #(
.A_SIGNED(A_SIGNED),
.B_SIGNED(B_SIGNED),
.A_WIDTH(A_WIDTH-(n-1)*(`DSP_A_MAXWIDTH-sign_headroom)),
.A_WIDTH(last_A_WIDTH),
.B_WIDTH(B_WIDTH),
.Y_WIDTH(last_Y_WIDTH)
) mul_slice_last (
.A(A[A_WIDTH-1 : (n-1)*(`DSP_A_MAXWIDTH-sign_headroom)]),
.A(A[A_WIDTH-1 -: last_A_WIDTH]),
.B(B),
.Y(last_partial)
);
@ -232,20 +217,17 @@ module \$__mul (A, B, Y);
end
localparam last_B_WIDTH = B_WIDTH-(n-1)*(`DSP_B_MAXWIDTH-sign_headroom);
if (A_SIGNED && B_SIGNED && last_B_WIDTH == 1)
assign last_partial = 0;
else
\$__mul #(
.A_SIGNED(A_SIGNED),
.B_SIGNED(B_SIGNED),
.A_WIDTH(A_WIDTH),
.B_WIDTH(last_B_WIDTH),
.Y_WIDTH(last_Y_WIDTH)
) mul_last (
.A(A),
.B(B[B_WIDTH-1 -: last_B_WIDTH]),
.Y(last_partial)
);
\$__mul #(
.A_SIGNED(A_SIGNED),
.B_SIGNED(B_SIGNED),
.A_WIDTH(A_WIDTH),
.B_WIDTH(last_B_WIDTH),
.Y_WIDTH(last_Y_WIDTH)
) mul_last (
.A(A),
.B(B[B_WIDTH-1 -: last_B_WIDTH]),
.Y(last_partial)
);
assign partial_sum[n-1] = (last_partial << (n-1)*(`DSP_B_MAXWIDTH-sign_headroom)) + partial_sum[n-2];
assign Y = partial_sum[n-1];
end