yosys/techlibs/quicklogic/qlf_k6n10f/arith_map.v

100 lines
2.5 KiB
Verilog

// Copyright 2020-2022 F4PGA Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// SPDX-License-Identifier: Apache-2.0
(* techmap_celltype = "$alu" *)
module _80_quicklogic_alu (A, B, CI, BI, X, Y, CO);
parameter A_SIGNED = 0;
parameter B_SIGNED = 0;
parameter A_WIDTH = 2;
parameter B_WIDTH = 2;
parameter Y_WIDTH = 2;
parameter _TECHMAP_CONSTVAL_CI_ = 0;
parameter _TECHMAP_CONSTMSK_CI_ = 0;
(* force_downto *)
input [A_WIDTH-1:0] A;
(* force_downto *)
input [B_WIDTH-1:0] B;
(* force_downto *)
output [Y_WIDTH-1:0] X, Y;
input CI, BI;
(* force_downto *)
output [Y_WIDTH-1:0] CO;
wire _TECHMAP_FAIL_ = Y_WIDTH <= 2;
(* 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;
genvar i;
wire co;
(* force_downto *)
//wire [Y_WIDTH-1:0] C = {CO, CI};
wire [Y_WIDTH:0] C;
(* force_downto *)
wire [Y_WIDTH-1:0] S = {AA ^ BB};
assign CO[Y_WIDTH-1:0] = C[Y_WIDTH:1];
//assign CO[Y_WIDTH-1] = co;
generate
adder_carry intermediate_adder (
.cin ( ),
.cout (C[0]),
.p (1'b0),
.g (CI),
.sumout ()
);
endgenerate
genvar i;
generate if (Y_WIDTH > 2) begin
for (i = 0; i < Y_WIDTH-2; i = i + 1) begin:slice
adder_carry my_adder (
.cin (C[i]),
.g (AA[i]),
.p (S[i]),
.cout (C[i+1]),
.sumout (Y[i])
);
end
end endgenerate
generate
adder_carry final_adder (
.cin (C[Y_WIDTH-2]),
.cout (),
.p (1'b0),
.g (1'b0),
.sumout (co)
);
endgenerate
assign Y[Y_WIDTH-2] = S[Y_WIDTH-2] ^ co;
assign C[Y_WIDTH-1] = S[Y_WIDTH-2] ? co : AA[Y_WIDTH-2];
assign Y[Y_WIDTH-1] = S[Y_WIDTH-1] ^ C[Y_WIDTH-1];
assign C[Y_WIDTH] = S[Y_WIDTH-1] ? C[Y_WIDTH-1] : AA[Y_WIDTH-1];
assign X = S;
endmodule