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Diffstat (limited to 'techlibs/fabulous/arith_map.v')
| -rw-r--r-- | techlibs/fabulous/arith_map.v | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/techlibs/fabulous/arith_map.v b/techlibs/fabulous/arith_map.v new file mode 100644 index 000000000..eca968556 --- /dev/null +++ b/techlibs/fabulous/arith_map.v @@ -0,0 +1,65 @@ +`default_nettype none + +`ifdef ARITH_ha +(* techmap_celltype = "$alu" *) +module _80_fabulous_ha_alu (A, B, CI, BI, X, Y, CO); + +parameter A_SIGNED = 0; +parameter B_SIGNED = 0; +parameter A_WIDTH = 1; +parameter B_WIDTH = 1; +parameter Y_WIDTH = 1; + +parameter _TECHMAP_CONSTMSK_CI_ = 0; +parameter _TECHMAP_CONSTVAL_CI_ = 0; + +(* force_downto *) +input [A_WIDTH-1:0] A; +(* force_downto *) +input [B_WIDTH-1:0] B; +input CI, BI; +(* force_downto *) +output [Y_WIDTH-1:0] X, Y, CO; + +(* force_downto *) +wire [Y_WIDTH-1:0] A_buf, B_buf; +\$pos #(.A_SIGNED(A_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf)); +\$pos #(.A_SIGNED(B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf)); + +(* force_downto *) +wire [Y_WIDTH-1:0] AA = A_buf; +(* force_downto *) +wire [Y_WIDTH-1:0] BB = BI ? ~B_buf : B_buf; +wire [Y_WIDTH:0] CARRY; + + +LUT4_HA #( + .INIT(16'b0), + .I0MUX(1'b1) +) carry_statrt ( + .I0(), .I1(CI), .I2(CI), .I3(), + .Ci(), + .Co(CARRY[0]) +); + +// Carry chain +genvar i; +generate for (i = 0; i < Y_WIDTH; i = i + 1) begin:slice + LUT4_HA #( + .INIT(16'b1001_0110_1001_0110), // full adder sum over (I2, I1, I0) + .I0MUX(1'b1) + ) lut_i ( + .I0(), .I1(AA[i]), .I2(BB[i]), .I3(), + .Ci(CARRY[i]), + .O(Y[i]), + .Co(CARRY[i+1]) + ); + + assign CO[i] = (AA[i] && BB[i]) || ((Y[i] ^ AA[i] ^ BB[i]) && (AA[i] || BB[i])); +end endgenerate + +assign X = AA ^ BB; + +endmodule +`endif + |