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Diffstat (limited to 'techlibs/ice40/arith_map.v')
| -rw-r--r-- | techlibs/ice40/arith_map.v | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/techlibs/ice40/arith_map.v b/techlibs/ice40/arith_map.v new file mode 100644 index 000000000..b0f66a2ac --- /dev/null +++ b/techlibs/ice40/arith_map.v @@ -0,0 +1,70 @@ +/* + * yosys -- Yosys Open SYnthesis Suite + * + * Copyright (C) 2012 Clifford Wolf <clifford@clifford.at> + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * + */ + +(* techmap_celltype = "$alu" *) +module _80_ice40_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; + + input [A_WIDTH-1:0] A; + input [B_WIDTH-1:0] B; + output [Y_WIDTH-1:0] X, Y; + + input CI, BI; + output [Y_WIDTH-1:0] CO; + + wire _TECHMAP_FAIL_ = Y_WIDTH <= 2; + + 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)); + + wire [Y_WIDTH-1:0] AA = A_buf; + wire [Y_WIDTH-1:0] BB = BI ? ~B_buf : B_buf; + wire [Y_WIDTH-1:0] C = {CO, CI}; + + genvar i; + generate for (i = 0; i < Y_WIDTH; i = i + 1) begin:slice + SB_CARRY carry ( + .I0(AA[i]), + .I1(BB[i]), + .CI(C[i]), + .CO(CO[i]) + ); + SB_LUT4 #( + // I0: 1010 1010 1010 1010 + // I1: 1100 1100 1100 1100 + // I2: 1111 0000 1111 0000 + // I3: 1111 1111 0000 0000 + .LUT_INIT(16'b 0110_1001_1001_0110) + ) adder ( + .I0(1'b0), + .I1(AA[i]), + .I2(BB[i]), + .I3(C[i]), + .O(Y[i]) + ); + end endgenerate + + assign X = AA ^ BB; +endmodule + |