我想请问卖报机的测试代码怎么编写？求解答

qwe2508

题目是设计一个卖报机，报纸价钱八角，纸币有1角，2角，5角，一元。该卖报机不考虑投币为大额面值等特殊情况
状态图我也画出来了，
代码是data_out=1表示给出报纸，data_out_return1=1表示找回1角硬币，data_out_return2=1表示找回2角硬币。

1. module auto_sellor (current_state,data_out,data_out_return1,data_out_return2,
   
2. clk,rst_n,data_in);
   
3. parameter state_width=3,data_in_width=3;
   
4. output [state_width-1:0] current_state;
   
5. output data_out, data_out_return1, data_out_return2;
   
6. input [data_in_width-1:0] data_in;
   
7. input clk, rst_n;
   
8. reg [state_width-1:0] current_state, next_state;
   
9. reg data_out, data_out_return1, data_out_return2;
   
10. always @(current_state or rst_n)
    
11. if (!rst_n)
    
12. next_state<=0;
    
13. else
    
14. case (current_state)
    
15. 3'b000: case (data_in)
    
16. 3'b000: begin
    
17. next_state<=3'b000;
    
18. data_out<=1'b0;
    
19. data_out_return1<=1'b0;
    
20. data_out_return2<=1'b0;
    
21. end
    
22. 3'b001: begin
    
23. next_state<=3'b001;
    
24. data_out<=1'b0;
    
25. data_out_return1<=1'b0;
    
26. data_out_return2<=1'b0;
    
27. end
    
28. 3'b010: begin
    
29. next_state<=3'b010;
    
30. data_out<=1'b0;
    
31. data_out_return1<=1'b0;
    
32. data_out_return2<=1'b0;
    
33. end
    
34. 3'b011: begin
    
35. next_state<=3'b101;
    
36. data_out<=1'b0;
    
37. data_out_return1<=1'b0;
    
38. data_out_return2<=1'b0;
    
39. end
    
40. 3'b100: begin
    
41. next_state<=3'b000;
    
42. data_out<=1'b1;
    
43. data_out_return1<=1'b0;
    
44. data_out_return2<=1'b1;
    
45. end
    
46. endcase
    
47. 3'b001: case (data_in)
    
48. 3'b000: begin
    
49. next_state<=3'b001;
    
50. data_out<=1'b0;
    
51. data_out_return1<=1'b0;
    
52. data_out_return2<=1'b0;
    
53. end
    
54. 3'b001: begin
    
55. next_state<=3'b010;
    
56. data_out<=1'b0;
    
57. data_out_return1<=1'b0;
    
58. data_out_return2<=1'b0;
    
59. end
    
60. 3'b010: begin
    
61. next_state<=3'b011;
    
62. data_out<=1'b0;
    
63. data_out_return1<=1'b0;
    
64. data_out_return2<=1'b0;
    
65. end
    
66. 3'b011: begin
    
67. next_state<=3'b110;
    
68. data_out<=1'b0;
    
69. data_out_return1<=1'b0;
    
70. data_out_return2<=1'b0;
    
71. end
    
72. endcase
    
73. 3'b010: case (data_in)
    
74. 3'b000: begin
    
75. next_state<=3'b010;
    
76. data_out<=1'b0;
    
77. data_out_return1<=1'b0;
    
78. data_out_return2<=1'b0;
    
79. end
    
80. 3'b001: begin
    
81. next_state<=3'b011;
    
82. data_out<=1'b0;
    
83. data_out_return1<=1'b0;
    
84. data_out_return2<=1'b0;
    
85. end
    
86. 3'b010: begin
    
87. next_state<=3'b100;
    
88. data_out<=1'b0;
    
89. data_out_return1<=1'b0;
    
90. data_out_return2<=1'b0;
    
91. end
    
92. 3'b011: begin
    
93. next_state<=3'b111;
    
94. data_out<=1'b0;
    
95. data_out_return1<=1'b0;
    
96. data_out_return2<=1'b0;
    
97. end
    
98. endcase
    
99. 3'b011: case (data_in)
    
100. 3'b000: begin
     
101. next_state<=3'b011;
     
102. data_out<=1'b0;
     
103. data_out_return1<=1'b0;
     
104. data_out_return2<=1'b0;
     
105. end
     
106. 3'b001: begin
     
107. next_state<=3'b100;
     
108. data_out<=1'b0;
     
109. data_out_return1<=1'b0;
     
110. data_out_return2<=1'b0;
     
111. end
     
112. 3'b010: begin
     
113. next_state<=3'b101;
     
114. data_out<=1'b0;
     
115. data_out_return1<=1'b0;
     
116. data_out_return2<=1'b0;
     
117. end
     
118. 3'b011: begin
     
119. next_state<=3'b000;
     
120. data_out<=1'b1;
     
121. data_out_return1<=1'b0;
     
122. data_out_return2<=1'b0;
     
123. end
     
124. endcase
     
125. 3'b100: case (data_in)
     
126. 3'b000: begin
     
127. next_state<=3'b000;
     
128. data_out<=1'b0;
     
129. data_out_return1<=1'b0;
     
130. data_out_return2<=1'b0;
     
131. end
     
132. 3'b001: begin
     
133. next_state<=3'b101;
     
134. data_out<=1'b0;
     
135. data_out_return1<=1'b0;
     
136. data_out_return2<=1'b0;
     
137. end
     
138. 3'b010: begin
     
139. next_state<=3'b110;
     
140. data_out<=1'b0;
     
141. data_out_return1<=1'b0;
     
142. data_out_return2<=1'b0;
     
143. end
     
144. 3'b011: begin
     
145. next_state<=3'b000;
     
146. data_out<=1'b1;
     
147. data_out_return1<=1'b1;
     
148. data_out_return2<=1'b0;
     
149. end
     
150. endcase
     
151. 3'b101: case (data_in)
     
152. 3'b000: begin
     
153. next_state<=3'b101;
     
154. data_out<=1'b0;
     
155. data_out_return1<=1'b0;
     
156. data_out_return2<=1'b0;
     
157. end
     
158. 3'b001: begin
     
159. next_state<=3'b110;
     
160. data_out<=1'b0;
     
161. data_out_return1<=1'b0;
     
162. data_out_return2<=1'b0;
     
163. end
     
164. 3'b010: begin
     
165. next_state<=3'b111;
     
166. data_out<=1'b0;
     
167. data_out_return1<=1'b0;
     
168. data_out_return2<=1'b0;
     
169. end
     
170. 3'b011: begin
     
171. next_state<=3'b000;
     
172. data_out<=1'b1;
     
173. data_out_return1<=1'b0;
     
174. data_out_return2<=1'b1;
     
175. end
     
176. endcase
     
177. 3'b110: case (data_in)
     
178. 3'b000: begin
     
179. next_state<=3'b110;
     
180. data_out<=1'b0;
     
181. data_out_return1<=1'b0;
     
182. data_out_return2<=1'b0;
     
183. end
     
184. 3'b001: begin
     
185. next_state<=3'b111;
     
186. data_out<=1'b0;
     
187. data_out_return1<=1'b0;
     
188. data_out_return2<=1'b0;
     
189. end
     
190. 3'b010: begin
     
191. next_state<=3'b000;
     
192. data_out<=1'b1;
     
193. data_out_return1<=1'b0;
     
194. data_out_return2<=1'b0;
     
195. end
     
196. endcase
     
197. 3'b111: case (data_in)
     
198. 3'b000: begin
     
199. next_state<=3'b111;
     
200. data_out<=1'b0;
     
201. data_out_return1<=1'b0;
     
202. data_out_return2<=1'b0;
     
203. end
     
204. 3'b001: begin
     
205. next_state<=3'b000;
     
206. data_out<=1'b1;
     
207. data_out_return1<=1'b0;
     
208. data_out_return2<=1'b0;
     
209. end
     
210. endcase
     
211. endcase
     
212. always @(posedge clk or rst_n)
     
213. if (!rst_n)
     
214. current_state<=3'b000;
     
215. else
     
216. current_state<=next_state;
     
217. endmodule
     

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qwe2508

其实我编了一个比较简单的状态机，我在每个状态下把他可能跳转的状态描述出来了，但是我测试代码不会写。所以我想请问一下论坛的各位大神