- Output depends on input and past behavior
- Requires use of storage elements

# Latches
## A Latch Built with NOR gates
Truth table:

| $S$ | $R$ | $Q_a$ | $Q_b$ |
| --- | --- | ----- | ----- |
| 0   | 0   | 0/1   | 1/0   |
| 0   | 1   | 0     | 1     |
| 1   | 0   | 1     | 0     |
| 1   | 1   | 0     | 0     |
![[Pasted image 20250303095542.png]]