Latch
see flip-flop, logic circuit
all latch › types can be turned into flip-flops and all flip-flop › types can be turned into latches
Gated Latch
gated latches are level-triggered whereas flip-flops are edge-triggered
all latches can be converted to gated latches with an enable input
Types
--- https://en.wikipedia.org/wiki/Flip-flop_(electronics)
logic circuit diagrams --- https://www.javatpoint.com/latches-in-digital-electronics
SR Latch
set-reset latch
representation truth table
| \(S\) | \(R\) | \(Q\) | comment |
|---|---|---|---|
| \(0\) | \(0\) | \(Q\) | no change |
| \(0\) | \(1\) | \(0\) | reset |
| \(1\) | \(0\) | \(1\) | set |
| \(1\) | \(1\) | --- | undefined |
D Latch
data latch, gated by default
representation truth table
| \(E\) | \(D\) | \(Q\) | comment |
|---|---|---|---|
| \(0\) | --- | \(Q\) | no change |
| \(1\) | \(0\) | \(0\) | data reset |
| \(1\) | \(1\) | \(1\) | data set |
JK Latch
same as SR latch, but with undefined states removed
representation truth table
| \(J\) | \(K\) | \(Q\) | comment |
|---|---|---|---|
| \(0\) | \(0\) | \(Q\) | no change |
| \(0\) | \(1\) | \(0\) | reset |
| \(1\) | \(0\) | \(1\) | set |
| \(1\) | \(1\) | \(\lnot Q\) | toggle |
T Latch
toggle latch
not used as its only state would be undefined