| /* | |
| * 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 | |