试用JK触发器和必要的门电路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.
根据题目的要求, 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 | Q2* | Q1* | Q0* | Z | J2 | K2 | J1 | K1 | J0 | K0 |
0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | × | 0 | × | 1 | × |
0 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | × | 1 | × | × | 1 |
0 | 0 | 1 | 0 | 0 | 1 | 1 | 0 | 0 | × | × | 0 | 1 | × |
0 | 0 | 1 | 1 | 1 | 0 | 0 | 0 | 1 | × | × | 1 | × | 1 |
0 | 1 | 0 | 0 | 1 | 0 | 1 | 0 | × | 0 | 0 | × | 1 | × |
0 | 1 | 0 | 1 | 0 | 0 | 0 | 1 | × | 1 | 0 | × | × | 1 |
0 | 1 | 1 | 0 | × | × | × | 0 | × | × | × | × | × | × |
0 | 1 | 1 | 1 | × | × | × | 0 | × | × | × | × | × | × |
1 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | × | 0 | × | 1 | × |
1 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | × | 1 | × | × | 1 |
1 | 0 | 1 | 0 | 0 | 1 | 1 | 0 | 0 | × | × | 0 | 1 | × |
1 | 0 | 1 | 1 | 1 | 0 | 0 | 0 | 1 | × | × | 1 | × | 1 |
1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | × | 1 | 0 | × | 0 | × |
1 | 1 | 0 | 1 | × | × | × | 0 | × | × | × | × | × | × |
1 | 1 | 1 | 0 | × | × | × | 0 | × | × | × | × | × | × |
1 | 1 | 1 | 1 | × | × | × | 0 | × | × | × | × | × | × |
根据状态激励表, 得到驱动方程和输出方程的逻辑表达式: J2=Q1Q0, J1=Q2'Q0, J0=X'+Q2', K2=X+Q0, K1=Q0, K0=1.
根据上面的分析, 绘制电路的原理图.