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
167
168
169
170
|
// DESCRIPTION: Verilator: SystemVerilog interface test module
//
// This file ONLY is placed into the Public Domain, for any use,
// without warranty, 2012 by Iztok Jeras.
// SPDX-License-Identifier: CC0-1.0
module t (/*AUTOARG*/
// Inputs
clk
);
input clk;
logic rst = 1'b1; // reset
integer rst_cnt = 0;
// reset is removed after a delay
always @ (posedge clk)
begin
rst_cnt <= rst_cnt + 1;
rst <= rst_cnt <= 3;
end
// counters
int cnt;
int cnt_src;
int cnt_drn;
// add all counters
assign cnt = cnt_src + cnt_drn + inf.cnt;
// finish report
always @ (posedge clk)
if (cnt == 3*16) begin
$write("*-* All Finished *-*\n");
$finish;
end
// interface instance
handshake inf (
.clk (clk),
.rst (rst)
);
// source instance
source #(
.RW (8),
.RP (8'b11100001)
) source (
.clk (clk),
.rst (rst),
.inf (inf),
.cnt (cnt_src)
);
// drain instance
drain #(
.RW (8),
.RP (8'b11010100)
) drain (
.clk (clk),
.rst (rst),
.inf (inf),
.cnt (cnt_drn)
);
endmodule : t
// interface definition
interface handshake #(
parameter int unsigned WC = 32
)(
input logic clk,
input logic rst
);
// modport signals
logic req; // request
logic grt; // grant
logic inc; // increment
// local signals
integer cnt; // counter
// source
modport src (
output req,
input grt
);
// drain
modport drn (
input req,
output grt
);
// incremet condition
assign inc = req & grt;
// local logic (counter)
always @ (posedge clk, posedge rst)
if (rst) cnt <= '0;
else cnt <= cnt + {31'h0, inc};
endinterface : handshake
// source module
module source #(
// random generator parameters
parameter int unsigned RW=1, // LFSR width
parameter bit [RW-1:0] RP='0, // LFSR polinom
parameter bit [RW-1:0] RR='1 // LFSR reset state
)(
input logic clk,
input logic rst,
handshake.src inf,
output integer cnt
);
// LFSR
logic [RW-1:0] rnd;
// LFSR in Galois form
always @ (posedge clk, posedge rst)
if (rst) rnd <= RR;
else rnd <= {rnd[0], rnd[RW-1:1]} ^ ({RW{rnd[0]}} & RP);
// counter
always @ (posedge clk, posedge rst)
if (rst) cnt <= 32'd0;
else cnt <= cnt + {31'd0, (inf.req & inf.grt)};
// request signal
assign inf.req = rnd[0];
endmodule : source
// drain module
module drain #(
// random generator parameters
parameter int unsigned RW=1, // LFSR width
parameter bit [RW-1:0] RP='0, // LFSR polinom
parameter bit [RW-1:0] RR='1 // LFSR reset state
)(
input logic clk,
input logic rst,
handshake.drn inf,
output integer cnt
);
// LFSR
logic [RW-1:0] rnd;
// LFSR in Galois form
always @ (posedge clk, posedge rst)
if (rst) rnd <= RR;
else rnd <= {rnd[0], rnd[RW-1:1]} ^ ({RW{rnd[0]}} & RP);
// counter
always @ (posedge clk, posedge rst)
if (rst) cnt <= 32'd0;
else cnt <= cnt + {31'd0, (inf.req & inf.grt)};
// grant signal
assign inf.grt = rnd[0];
endmodule : drain
|
