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/*
* 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.
*
* ---
*
* The internal logic cell simulation library.
*
* This verilog library contains simple simulation models for the internal
* logic cells ($_INV_ , $_AND_ , ...) that are generated by the default technology
* mapper (see "stdcells.v" in this directory) and expected by the "abc" pass.
*
*/
module \$_INV_ (A, Y);
input A;
output Y;
assign Y = ~A;
endmodule
module \$_AND_ (A, B, Y);
input A, B;
output Y;
assign Y = A & B;
endmodule
module \$_OR_ (A, B, Y);
input A, B;
output Y;
assign Y = A | B;
endmodule
module \$_XOR_ (A, B, Y);
input A, B;
output Y;
assign Y = A ^ B;
endmodule
module \$_MUX_ (A, B, S, Y);
input A, B, S;
output reg Y;
always @* begin
if (S)
Y = B;
else
Y = A;
end
endmodule
module \$_DFF_N_ (D, Q, C);
input D, C;
output reg Q;
always @(negedge C) begin
Q <= D;
end
endmodule
module \$_DFF_P_ (D, Q, C);
input D, C;
output reg Q;
always @(posedge C) begin
Q <= D;
end
endmodule
module \$_DFF_NN0_ (D, Q, C, R);
input D, C, R;
output reg Q;
always @(negedge C or negedge R) begin
if (R == 0)
Q <= 0;
else
Q <= D;
end
endmodule
module \$_DFF_NN1_ (D, Q, C, R);
input D, C, R;
output reg Q;
always @(negedge C or negedge R) begin
if (R == 0)
Q <= 1;
else
Q <= D;
end
endmodule
module \$_DFF_NP0_ (D, Q, C, R);
input D, C, R;
output reg Q;
always @(negedge C or posedge R) begin
if (R == 1)
Q <= 0;
else
Q <= D;
end
endmodule
module \$_DFF_NP1_ (D, Q, C, R);
input D, C, R;
output reg Q;
always @(negedge C or posedge R) begin
if (R == 1)
Q <= 1;
else
Q <= D;
end
endmodule
module \$_DFF_PN0_ (D, Q, C, R);
input D, C, R;
output reg Q;
always @(posedge C or negedge R) begin
if (R == 0)
Q <= 0;
else
Q <= D;
end
endmodule
module \$_DFF_PN1_ (D, Q, C, R);
input D, C, R;
output reg Q;
always @(posedge C or negedge R) begin
if (R == 0)
Q <= 1;
else
Q <= D;
end
endmodule
module \$_DFF_PP0_ (D, Q, C, R);
input D, C, R;
output reg Q;
always @(posedge C or posedge R) begin
if (R == 1)
Q <= 0;
else
Q <= D;
end
endmodule
module \$_DFF_PP1_ (D, Q, C, R);
input D, C, R;
output reg Q;
always @(posedge C or posedge R) begin
if (R == 1)
Q <= 1;
else
Q <= D;
end
endmodule
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