1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
/*
* 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 (_NOT_, _AND_, ...) that are generated by the default technology
* mapper (see "stdcells.v" in this directory) and expected by the "abc" pass.
*
*/
module _NOT_(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
|
