Sách điện số/Bộ phận điện số/Bộ ghi nhận điện số

SR Register

Enable	S	R		Q	Q
0	0	0		Latch
0	0	1		Latch
0	1	0		Latch
0	1	1		Latch
1	0	0		Latch
1	0	1		0	1
1	1	0		1	0
1	1	1		Metastable

D register

Enable	D		Q	Q
0	0		Latch
0	1		Latch
1	0		0	1
1	1		1	0

$Q_{next}=T\oplus Q=T{\overline {Q}}+{\overline {T}}Q$

and can be described either of the following tables:

T register

A circuit symbol for a T-type flip-flop: T is the toggle input and Q is the stored data output.

Characteristic table T Q Qnext Comment 0 0 0 Hold state 0 1 1 1 0 1 Toggle 1 1 0

Excitation table Q Qnext T 0 0 0 0 1 1 1 0 1 1 1 0

JK register

Symbol for a JK flip-flop

Characteristic table

J	K		Qnext	Comment
0	0		Qprev	Hold state
0	1		0	Reset
1	0		1	Set
1	1		Qprev	Toggle

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Excitation table

Q	Qnext		J	K	Comment
0	0		0	X	Hold state
0	1		1	X	Set
1	0		X	1	Reset
1	1		X	0	Hold state