13 March, 2000

The quiz

Homework and quizes

Flip-flops

memory elements
common features
- control/data input
- clock
  - positive edge
  - negative edge
- asynchronous set and clear
common types
- S R
- J K
- T
- D

Tables for flip-flops

S	R	Q
SR flip flop
characteristic table
0	0	Q
0	1	0
1	0	1
1	1

Q_old	Q_new	S	R
SR flip flop
excitation table
0	0	0	X
0	1	1	0
1	0	0	1
1	1	X	0

J	K	Q
JK flip flop
characteristic table
0	0	Q
0	1	0
1	0	1
1	1	Q'

Q_old	Q_new	J	K
JK flip flop
excitation table
0	0	0	X
0	1	1	X
1	0	X	1
1	1	X	0

D	Q
D flip flop
characteristic table
0	0
1	1

Q_old	Q_new	D
D flip flop
excitation table
0	0	0
0	1	1
1	0	0
1	1	1

T	Q
T flip flop
characteristic table
0	Q
1	Q'

Q_old	Q_new	T
T flip flop
excitation table
0	0	0
0	1	1
1	0	1
1	1	0