blob: 0aa36d9ab1b2a131da98642f21554742c64ef650 (
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
|
module top( //top module
CLK,
BUT1,
BUT2,
LED1,
LED2
);
input CLK; //input 100Mhz clock
input BUT1; //input signal from button 1
input BUT2; //input signal from button 2
output LED1; //output signal to LED1
output LED2; //output signal to LED2
reg BUT1_r; //register to keep button 1 state
reg BUT2_r; //register to keep button 2 state
reg LED1_m0_r; //LED1 value in mode = 0
reg LED2_m0_r; //LED2 value in mode = 0
reg LED1_m1_r; //LED1 value in mode = 1
reg LED2_m1_r; //LED2 value in mode = 1
reg [14:0] cntr; // 15 bit counter for LED blink timing
reg [14:0] rst_cnt=0; // 15 bit counter for button debounce
reg mode=1; //mode set to 1 initially
reg [11:0] clk_div; // 12 bit counter
wire clk_24KHz; //signal with approx 24KHz clock
wire reset; //used for button debounce
assign reset = rst_cnt[14]; //reset signal is connected to bit15 of rst_cnt
assign LED1 = mode ? LED1_m1_r : LED1_m0_r; //multiplexer controlled by mode which connects LED1_m1_r or LED1_m0_r to LED1
assign LED2 = mode ? LED2_m1_r : LED2_m0_r; //multiplexer controlled by mode which connects LED2_m1_r or LED2_m0_r to LED2
assign clk_24KHz = clk_div[11]; //100 000 000 Hz / 4096 = 24414 Hz
always @ (posedge CLK) begin //on each positive edge of 100Mhz clock increment clk_div
clk_div <= clk_div + 12'b1;
end
always @ (posedge clk_24KHz) begin //on each positive edge of 24414Hz clock
BUT1_r <= BUT1; //capture button 1 state to BUT1_r
BUT2_r <= BUT2; //capture button 2 state to BUT2_r
cntr <= cntr + 15'd1; //increment cntr LED blink counter
if(reset == 1'b0) begin //if bit15 of rst_cnt is not set yet
rst_cnt <= rst_cnt + 15'd1; //increment the counter rst_cnt
end
if(BUT1_r == 1'b0 && BUT2_r == 1'b0 && reset == 1'b1) begin //if bit15 of rst_cnt is set and both buttons are pressed
mode <= mode ^ 1'b1; //toggle the mode
rst_cnt <= 15'd0; //clear debounce rst_cnt
end
LED1_m0_r <= ~BUT1_r; //copy inversed state of button 1 to LED1_m0_r
LED2_m0_r <= ~BUT2_r; //copy inversed state of button 2 to LED2_m0_r
if(cntr == 15'd12207) begin //when 0.5s pass
LED1_m1_r <= 1'b0; //reset LED1_m1_r
LED2_m1_r <= 1'b1; //set LED2_m1_r
end
if(cntr > 15'd24414) begin //when 1.0s pass
cntr <= 15'd0; //clear cntr
LED1_m1_r <= 1'b1; //set LED1_m1_r
LED2_m1_r <= 1'b0; //reset LED2_m1_r
end
end
endmodule
|
