PWM的LEDG灯控制
通过PWM控制LEDG灯的频率
1
module pwm(
2
clk,
3
reset_n,
4
high_dur,
5
total_dur,
6
pwm,
7
toggle
8
);
9
10
input
clk;
11
input
reset_n;
12
input
[
31
:
0
] high_dur;
13
input
[
31
:
0
] total_dur;
14
output
pwm;
15
output
reg toggle;
16
17
reg [
31
:
0
] tick;
18
19
always @ (posedge clk
or
negedge reset_n)
20
begin
21
if
(
!
reset_n)
22
begin
23
tick
<=
0
;
24
toggle
<=
0
;
25
end
26
else
if
(tick
>=
total_dur)
27
begin
28
tick
<=
0
;
29
toggle
<=
~
toggle;
30
end
31
else
32
tick
<=
tick
+
1
;
33
end
34
35
assign pwm
=
(tick
<
high_dur)
?
1
'
b1:1
'
b0;
36
37
endmodule
38
可以通过 SW按钮来控制LED
1
module DE0_PWM_LED(
2
//////////////////
// Clock Input
//////////////////
//
3
CLOCK_50,
//
50 MHz
4
////////////////////////
LED
////////////////////////
5
LEDG,
//
LED Green[9:0]
6
//////////////////
// DPDT Switch
//////////////////
//
7
SW,
//
Toggle Switch[9:0]
8
reset_n
9
);
10
11
////////////////////////
Clock Input
////////////////////////
12
input
CLOCK_50;
//
50 MHz
13
///////////////////////////
/ LED
///////////////////////////
/
14
output
[
9
:
0
] LEDG;
//
LED Green[9:0]
15
////////////////////////
DPDT Switch
////////////////////////
16
input
[
9
:
0
] SW;
//
Toggle Switch[9:0]
17
input
reset_n;
18
//
=======================================================
19
//
REG/WIRE declarations
20
//
=======================================================
21
wire reset_n;
22
//
assign reset_n = 1'b1;
23
wire [
9
:
0
] MAX_LIGHT;
24
//
`define MAX_LIGHT 8'hFF
25
wire [
11
:
0
] MAX_LIGHT_TICK;
26
//
`define MAX_LIGHT_TICK 11'h7FF
27
28
reg [
8
:
0
] light;
29
reg [
9
:
0
] light_tick;
30
reg lighter;
31
wire toggle;
32
33
34
//
=======================================================
35
//
Structural coding
36
//
=======================================================
37
38
//
39
always @ (posedge toggle
or
negedge reset_n)
40
begin
41
if
(
!
reset_n)
42
begin
43
light_tick
<=
0
;
44
light
<=
0
;
45
lighter
<=
1
'
b1;
46
end
47
else
if
(light_tick
>=
MAX_LIGHT_TICK)
48
begin
49
light_tick
<=
0
;
50
if
(lighter)
51
begin
52
if
(light
>=
MAX_LIGHT)
53
lighter
<=
1
'
b0;
54
else
55
light
<=
light
+
1
'
b1;
56
end
57
else
58
begin
59
if
(light
==
0
)
60
lighter
<=
1
'
b1;
61
else
62
light
<=
light
-
1
'
b1;
63
end
64
end
65
else
66
light_tick
<=
light_tick
+
1
'
b1;
67
end
68
69
wire led_pwm;
70
wire [
8
:
0
] linear_light;
71
//
linearlize process: input pwm->led illuminance (user can optimal linearity here)
72
assign linear_light
=
(light
<
MAX_LIGHT
/
2
)
?
light
/
4
:(MAX_LIGHT
/
10
+
(light
-
MAX_LIGHT
/
2
)
*
9
/
4
);
73
74
pwm pwm_inst(
75
.clk(CLOCK_50),
76
.reset_n(reset_n),
77
.high_dur(linear_light),
78
.total_dur(MAX_LIGHT),
79
.pwm(led_pwm),
80
.toggle(toggle)
81
);
82
83
assign LEDG[
0
]
=
led_pwm;
84
assign LEDG[
1
]
=
led_pwm;
85
assign LEDG[
2
]
=
led_pwm;
86
assign LEDG[
3
]
=
led_pwm;
87
assign LEDG[
4
]
=
led_pwm;
88
assign LEDG[
5
]
=
led_pwm;
89
assign LEDG[
6
]
=
led_pwm;
90
assign LEDG[
7
]
=
led_pwm;
91
assign LEDG[
8
]
=
led_pwm;
92
assign LEDG[
9
]
=
led_pwm;
93
94
95
assign MAX_LIGHT
=
SW;
96
assign MAX_LIGHT_TICK
=
MAX_LIGHT
<<
1
;
97
98
endmodule
99
100
101