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| author | Eddie Hung <eddie@fpgeh.com> | 2019-07-09 10:59:37 -0700 |
|---|---|---|
| committer | Eddie Hung <eddie@fpgeh.com> | 2019-07-09 10:59:37 -0700 |
| commit | 93522b0ae15466297e45edecf55f7e33c4ebcc1c (patch) | |
| tree | 7ad1ba2aa6f31d02788cae0af6f9b803b02f4a5f /techlibs/xilinx | |
| parent | c8649953431d3789296c4a7c1bd559ec136af6e3 (diff) | |
| download | yosys-93522b0ae15466297e45edecf55f7e33c4ebcc1c.tar.gz yosys-93522b0ae15466297e45edecf55f7e33c4ebcc1c.tar.bz2 yosys-93522b0ae15466297e45edecf55f7e33c4ebcc1c.zip | |
Extend during mux decomposition with 1'bx
Diffstat (limited to 'techlibs/xilinx')
| -rw-r--r-- | techlibs/xilinx/cells_map.v | 27 |
1 files changed, 3 insertions, 24 deletions
diff --git a/techlibs/xilinx/cells_map.v b/techlibs/xilinx/cells_map.v index 233a56003..e81ff8f53 100644 --- a/techlibs/xilinx/cells_map.v +++ b/techlibs/xilinx/cells_map.v @@ -203,25 +203,11 @@ module \$__XILINX_SHIFTX (A, B, Y); MUXF7 fpga_hard_mux (.I0(A[0]), .I1(A[1]), .S(B[0]), .O(Y)); end else if (A_WIDTH <= 4) begin - // Rather than extend with 1'bx which gets flattened to 1'b0 - // causing the "don't care" status to get lost, extend with MSBs - // so that we can recognise again later when mapping MUXF78 - wire [4-1:0] Ax; - if (A_WIDTH == 4) - assign Ax = A; - else - assign Ax = {A[1-:4-A_WIDTH], A}; + wire [4-1:0] Ax = {{{4-A_WIDTH}{1'bx}}, A}; \$__XILINX_MUXF78 fpga_hard_mux (.I0(Ax[0]), .I1(Ax[2]), .I2(Ax[1]), .I3(Ax[3]), .S0(B[1]), .S1(B[0]), .O(Y)); end else if (A_WIDTH <= 8) begin - // Rather than extend with 1'bx which gets flattened to 1'b0 - // causing the "don't care" status to get lost, extend with MSBs - // so that we can recognise again later when mapping MUXF78 - wire [8-1:0] Ax; - if (A_WIDTH == 8) - assign Ax = A; - else - assign Ax = {A[3-:8-A_WIDTH], A}; + wire [8-1:0] Ax = {{{8-A_WIDTH}{1'bx}}, A}; wire T0 = B[2] ? Ax[4] : Ax[0]; wire T1 = B[2] ? Ax[5] : Ax[1]; wire T2 = B[2] ? Ax[6] : Ax[2]; @@ -229,14 +215,7 @@ module \$__XILINX_SHIFTX (A, B, Y); \$__XILINX_MUXF78 fpga_hard_mux (.I0(T0), .I1(T2), .I2(T1), .I3(T3), .S0(B[1]), .S1(B[0]), .O(Y)); end else if (A_WIDTH <= 16) begin - // Rather than extend with 1'bx which gets flattened to 1'b0 - // causing the "don't care" status to get lost, extend with MSBs - // so that we can recognise again later when mapping MUXF78 - wire [16-1:0] Ax; - if (A_WIDTH == 16) - assign Ax = A; - else - assign Ax = {A[7-:16-A_WIDTH], A}; + wire [16-1:0] Ax = {{{16-A_WIDTH}{1'bx}}, A}; wire T0 = B[2] ? B[3] ? Ax[12] : Ax[4] : B[3] ? Ax[ 8] : Ax[0]; wire T1 = B[2] ? B[3] ? Ax[13] : Ax[5] |