试用D触发器和74151设计一同步时序逻辑电路, 当X=1时电路实现5进制计数器功能, 初态为000; 当X=0时, 电路实现6进制计数器功能, 初态为000.
根据题目的描述, 得到状态表.
状态表 | |||||||
X | Q2 | Q1 | Q0 | Q2* | Q1* | Q0* | Z |
0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
0 | 0 | 0 | 1 | 0 | 1 | 0 | 0 |
0 | 0 | 1 | 0 | 0 | 1 | 1 | 0 |
0 | 0 | 1 | 1 | 1 | 0 | 0 | 0 |
0 | 1 | 0 | 0 | 1 | 0 | 1 | 0 |
0 | 1 | 0 | 1 | 0 | 0 | 0 | 1 |
0 | 1 | 1 | 0 | × | × | × | 0 |
0 | 1 | 1 | 1 | × | × | × | 0 |
1 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
1 | 0 | 0 | 1 | 0 | 1 | 0 | 0 |
1 | 0 | 1 | 0 | 0 | 1 | 1 | 0 |
1 | 0 | 1 | 1 | 1 | 0 | 0 | 0 |
1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 |
1 | 1 | 0 | 1 | × | × | × | 0 |
1 | 1 | 1 | 0 | × | × | × | 0 |
1 | 1 | 1 | 1 | × | × | × | 0 |
根据状态表, 得到状态激励表.
状态激励表 | |||||||
X | Q2 | Q1 | Q0 | D2 | D1 | D0 | Z |
0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
0 | 0 | 0 | 1 | 0 | 1 | 0 | 0 |
0 | 0 | 1 | 0 | 0 | 1 | 1 | 0 |
0 | 0 | 1 | 1 | 1 | 0 | 0 | 0 |
0 | 1 | 0 | 0 | 1 | 0 | 1 | 0 |
0 | 1 | 0 | 1 | 0 | 0 | 0 | 1 |
0 | 1 | 1 | 0 | × | × | × | 0 |
0 | 1 | 1 | 1 | × | × | × | 0 |
1 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
1 | 0 | 0 | 1 | 0 | 1 | 0 | 0 |
1 | 0 | 1 | 0 | 0 | 1 | 1 | 0 |
1 | 0 | 1 | 1 | 1 | 0 | 0 | 0 |
1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 |
1 | 1 | 0 | 1 | × | × | × | 0 |
1 | 1 | 1 | 0 | × | × | × | 0 |
1 | 1 | 1 | 1 | × | × | × | 0 |
用4片74151分别实现D0、D1、D2和Z的逻辑表达式.
根据上面的分析, 绘制电路的原理图.