前几天在调试一个项目时想用SignaTap II查看状态机的状态，经过琢磨后发现了使用方法。保存与此，以便以后忘记了再来复习。
附上一个小的状态机测试程序，虽然代码不够完善，但也能达到示范目的。
1 module statetest(
2 input [0:0] iKEY,
3 input [8:0] iSW,
4 input iCLK_50,
5 output reg [7:0] oLEDG);
6 //wire [7:0] oLEDG;
7 localparam IDLE =0,
8 LED1=1,
9 LED2=2,
10 LED3=3,
11 LED4=4,
12 LED5=5,
13 LED6=6,
14 LED7=7,
15 LED8=8;
16
17 reg [7:0] state_reg,state_next;
18
19 always @(posedge iCLK_50,negedge iKEY[0])
20 if(!iKEY[0])
21 state_reg<=IDLE;
22 else
23 state_reg<=state_next;
24
25
26 always @*
27 begin
28 state_next=state_reg;
29
30 case (state_reg)
31 IDLE:
32 begin
33 oLEDG=8'b00000000;
34 if(iSW[0])
35 state_next=LED1;
36 else
37 state_next=IDLE;
38 end
39 LED1:
40 begin
41 oLEDG=8'b00000001;
42 if(iSW[1])
43 state_next=LED2;
44 else
45 state_next=LED1;
46 end
47 LED2:
48 begin
49 oLEDG=8'b00000010;
50 if(iSW[2])
51 state_next=LED3;
52 else
53 state_next=LED2;
54 end
55 LED3:
56 begin
57 oLEDG=8'b00000100;
58 if(iSW[3])
59 state_next=LED4;
60 else
61 state_next=LED3;
62 end
63 LED4:
64 begin
65 oLEDG=8'b00001000;
66 if(iSW[4])
67 state_next=LED5;
68 else
69 state_next=LED4;
70 end
71 LED5:
72 begin
73 oLEDG=8'b00010000;
74 if(iSW[5])
75 state_next=LED6;
76 else
77 state_next=LED5;
78 end
79 LED6:
80 begin
81 oLEDG=8'b00100000;
82 if(iSW[6])
83 state_next=LED7;
84 else
85 state_next=LED6;
86 end
87 LED7:
88 begin
89 oLEDG=8'b01000000;
90 if(iSW[7])
91 state_next=LED8;
92 else
93 state_next=LED7;
94 end
95 LED8:
96 begin
97 oLEDG=8'b10000000;
98 if(iSW[8])
99 state_next=IDLE;
100 else
101 state_next=LED8;
102 end
103 default:
104 state_next=IDLE;
105 endcase
106 end
107 endmodule
108
109
