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Fix (do not) permute LUT inputs, but permute mux selects

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This commit is contained in:
Eddie Hung 2019-06-18 09:49:57 -07:00
parent 608a95eb01
commit da3d2eedd2
1 changed files with 33 additions and 31 deletions
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64
techlibs/xilinx/lut_map.v
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@ -29,30 +29,32 @@ module \$lut (A, Y);
input [WIDTH-1:0] A; input [WIDTH-1:0] A;
output Y; output Y;
// Need to swap input ordering, and fix init accordingly, // Need to swap input ordering of wide LUTs, and fix init accordingly,
// to match ABC's expectation of LUT inputs in non-decreasing // to match ABC's expectation of LUT inputs in non-decreasing
// delay order // delay order
function [WIDTH-1:0] permute_index; function [WIDTH-1:0] permute_index;
input [WIDTH-1:0] i; input [WIDTH-1:0] i;
integer j; integer j;
begin begin
permute_index = 0; if (WIDTH == 7)
for (j = 0; j < WIDTH; j = j + 1) permute_index = { i[5:0], i[6] };
permute_index[WIDTH-1 - j] = i[j]; else if (WIDTH == 8)
permute_index = { i[5:0], i[6], i[7] };
else
permute_index = i;
end end
endfunction endfunction
function [2**WIDTH-1:0] permute_init; function [2**WIDTH-1:0] permute_init;
input [2**WIDTH-1:0] orig;
integer i; integer i;
begin begin
permute_init = 0; permute_init = 0;
for (i = 0; i < 2**WIDTH; i = i + 1) for (i = 0; i < 2**WIDTH; i = i + 1)
permute_init[i] = orig[permute_index(i)]; permute_init[i] = LUT[permute_index(i)];
end end
endfunction endfunction
parameter [2**WIDTH-1:0] P_LUT = permute_init(LUT); parameter [2**WIDTH-1:0] P_LUT = permute_init();
generate generate
if (WIDTH == 1) begin if (WIDTH == 1) begin
@ -61,54 +63,54 @@ module \$lut (A, Y);
end else end else
if (WIDTH == 2) begin if (WIDTH == 2) begin
LUT2 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), LUT2 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y),
.I0(A[1]), .I1(A[0])); .I0(A[0]), .I1(A[1]));
end else end else
if (WIDTH == 3) begin if (WIDTH == 3) begin
LUT3 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), LUT3 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y),
.I0(A[2]), .I1(A[1]), .I2(A[0])); .I0(A[0]), .I1(A[1]), .I2(A[2]));
end else end else
if (WIDTH == 4) begin if (WIDTH == 4) begin
LUT4 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), LUT4 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y),
.I0(A[3]), .I1(A[2]), .I2(A[1]), .I0(A[0]), .I1(A[1]), .I2(A[2]),
.I3(A[0])); .I3(A[3]));
end else end else
if (WIDTH == 5) begin if (WIDTH == 5) begin
LUT5 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), LUT5 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y),
.I0(A[4]), .I1(A[3]), .I2(A[2]), .I0(A[0]), .I1(A[1]), .I2(A[2]),
.I3(A[1]), .I4(A[0])); .I3(A[3]), .I4(A[4]));
end else end else
if (WIDTH == 6) begin if (WIDTH == 6) begin
LUT6 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), LUT6 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y),
.I0(A[5]), .I1(A[4]), .I2(A[3]), .I0(A[0]), .I1(A[1]), .I2(A[2]),
.I3(A[2]), .I4(A[1]), .I5(A[0])); .I3(A[3]), .I4(A[4]), .I5(A[5]));
end else end else
if (WIDTH == 7) begin if (WIDTH == 7) begin
wire T0, T1; wire T0, T1;
LUT6 #(.INIT(P_LUT[63:0])) fpga_lut_0 (.O(T0), LUT6 #(.INIT(P_LUT[63:0])) fpga_lut_0 (.O(T0),
.I0(A[5]), .I1(A[4]), .I2(A[3]), .I0(A[1]), .I1(A[2]), .I2(A[3]),
.I3(A[2]), .I4(A[1]), .I5(A[0])); .I3(A[4]), .I4(A[5]), .I5(A[6]));
LUT6 #(.INIT(P_LUT[127:64])) fpga_lut_1 (.O(T1), LUT6 #(.INIT(P_LUT[127:64])) fpga_lut_1 (.O(T1),
.I0(A[5]), .I1(A[4]), .I2(A[3]), .I0(A[1]), .I1(A[2]), .I2(A[3]),
.I3(A[2]), .I4(A[1]), .I5(A[0])); .I3(A[4]), .I4(A[5]), .I5(A[6]));
MUXF7 fpga_mux_0 (.O(Y), .I0(T0), .I1(T1), .S(A[6])); MUXF7 fpga_mux_0 (.O(Y), .I0(T0), .I1(T1), .S(A[0]));
end else end else
if (WIDTH == 8) begin if (WIDTH == 8) begin
wire T0, T1, T2, T3, T4, T5; wire T0, T1, T2, T3, T4, T5;
LUT6 #(.INIT(P_LUT[63:0])) fpga_lut_0 (.O(T0), LUT6 #(.INIT(P_LUT[63:0])) fpga_lut_0 (.O(T0),
.I0(A[5]), .I1(A[4]), .I2(A[3]), .I0(A[2]), .I1(A[3]), .I2(A[4]),
.I3(A[2]), .I4(A[1]), .I5(A[0])); .I3(A[5]), .I4(A[6]), .I5(A[7]));
LUT6 #(.INIT(P_LUT[127:64])) fpga_lut_1 (.O(T1), LUT6 #(.INIT(P_LUT[127:64])) fpga_lut_1 (.O(T1),
.I0(A[5]), .I1(A[4]), .I2(A[3]), .I0(A[2]), .I1(A[3]), .I2(A[4]),
.I3(A[2]), .I4(A[1]), .I5(A[0])); .I3(A[5]), .I4(A[6]), .I5(A[7]));
LUT6 #(.INIT(P_LUT[191:128])) fpga_lut_2 (.O(T2), LUT6 #(.INIT(P_LUT[191:128])) fpga_lut_2 (.O(T2),
.I0(A[5]), .I1(A[4]), .I2(A[3]), .I0(A[2]), .I1(A[3]), .I2(A[4]),
.I3(A[2]), .I4(A[1]), .I5(A[0])); .I3(A[5]), .I4(A[6]), .I5(A[7]));
LUT6 #(.INIT(P_LUT[255:192])) fpga_lut_3 (.O(T3), LUT6 #(.INIT(P_LUT[255:192])) fpga_lut_3 (.O(T3),
.I0(A[5]), .I1(A[4]), .I2(A[3]), .I0(A[2]), .I1(A[3]), .I2(A[4]),
.I3(A[2]), .I4(A[1]), .I5(A[0])); .I3(A[5]), .I4(A[6]), .I5(A[7]));
MUXF7 fpga_mux_0 (.O(T4), .I0(T0), .I1(T1), .S(A[6])); MUXF7 fpga_mux_0 (.O(T4), .I0(T0), .I1(T1), .S(A[1]));
MUXF7 fpga_mux_1 (.O(T5), .I0(T2), .I1(T3), .S(A[6])); MUXF7 fpga_mux_1 (.O(T5), .I0(T2), .I1(T3), .S(A[1]));
MUXF8 fpga_mux_2 (.O(Y), .I0(T4), .I1(T5), .S(A[7])); MUXF8 fpga_mux_2 (.O(Y), .I0(T4), .I1(T5), .S(A[0]));
end else begin end else begin
wire _TECHMAP_FAIL_ = 1; wire _TECHMAP_FAIL_ = 1;
end end