The D-latch is a multivibrator latch circuit without the illegal input state that the SR latch has when both inputs are high. The D-latch is known as a transparent latch. This means that as long as the gated signal G is high, the signal on D is propagated through the latch to the output.
The D-input is driven by the even LUT output (LUT0), and the G-input is driven by the odd LUT output (LUT1).
Figure 1. Gated D-Latch
| G | D | OUT |
|---|---|---|
| 0 | X | Hold state (no change) |
| 1 | 0 | Clear |
| 1 | 1 | Set |