OpenFPGA/yosys/techlibs/ecp5/arith_map.v

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/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2012 Clifford Wolf <clifford@clifford.at>
* Copyright (C) 2018 David Shah <dave@ds0.me>
*
* 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_ecp5_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 <= 4;
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));
function integer round_up2;
input integer N;
begin
round_up2 = ((N + 1) / 2) * 2;
end
endfunction
localparam Y_WIDTH2 = round_up2(Y_WIDTH);
wire [Y_WIDTH2-1:0] AA = A_buf;
wire [Y_WIDTH2-1:0] BB = BI ? ~B_buf : B_buf;
wire [Y_WIDTH2-1:0] C = {CO, CI};
wire [Y_WIDTH2-1:0] FCO, Y1;
genvar i;
generate for (i = 0; i < Y_WIDTH2; i = i + 2) begin:slice
CCU2C #(
.INIT0(16'b0110011010101010),
.INIT1(16'b0110011010101010),
.INJECT1_0("NO"),
.INJECT1_1("NO")
) ccu2c_i (
.CIN(C[i]),
.A0(AA[i]), .B0(BB[i]), .C0(1'b0), .D0(1'b1),
.A1(AA[i+1]), .B1(BB[i+1]), .C1(1'b0), .D1(1'b1),
.S0(Y[i]), .S1(Y1[i]),
.COUT(FCO[i])
);
assign CO[i] = (AA[i] && BB[i]) || (C[i] && (AA[i] || BB[i]));
if (i+1 < Y_WIDTH) begin
assign CO[i+1] = FCO[i];
assign Y[i+1] = Y1[i];
end
end endgenerate
assign X = AA ^ BB;
endmodule