blob: 849a26c542b3aeefb6fd60d2bb14e888b1059238 (
plain)
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
|
library ieee;
use ieee.std_logic_1164.all;
entity sequencer is
generic (
seq : string
);
port (
clk : in std_logic;
data : out std_logic
);
end entity sequencer;
architecture rtl of sequencer is
signal index : natural := seq'low;
signal ch : character;
function to_bit (a : in character) return std_logic is
variable ret : std_logic;
begin
case a is
when '0' | '_' => ret := '0';
when '1' | '-' => ret := '1';
when others => ret := 'X';
end case;
return ret;
end function to_bit;
begin
process (clk) is
begin
if rising_edge(clk) then
if (index < seq'high) then
index <= index + 1;
end if;
end if;
end process;
ch <= seq(index);
data <= to_bit(ch);
end architecture rtl;
library ieee;
use ieee.std_logic_1164.all;
entity issue is
port (
clk : in std_logic
);
end entity issue;
architecture psl of issue is
component sequencer is
generic (
seq : string
);
port (
clk : in std_logic;
data : out std_logic
);
end component sequencer;
signal a, b : std_logic;
begin
-- 01234567890
SEQ_A : sequencer generic map ("__-_-______") port map (clk, a);
SEQ_B : sequencer generic map ("_____-_-___") port map (clk, b);
-- All is sensitive to rising edge of clk
default clock is rising_edge(clk);
-- This assertion holds
NEXT_EVENT_a : assert always (a -> next_e[3 to 5] (b));
end architecture psl;
|
