LDE_1

Transparent Data Latch with Gate Enable and Inverted Gate

LDE_1 is a transparent data latch with data (D) and gate enable (GE) inputs. Output Q reflects the data (D) while the gate (G) input is Low and gate enable (GE) is High. The data on the D input during the Low-to-High gate transition is stored in the latch. The data on the Q output remains unchanged as long as G is High or GE is Low.

The latch is asynchronously cleared, output Low, when power is applied. Virtex simulates power-on when global set/reset (GSR) is active. GSR defaults to active-High but can be inverted by adding an inverter in front of the GSR input of the STARTUP_VIRTEX symbol.

Inputs			Outputs
GE	G	D	Q
0	X	X	No Chg
1	0	0	0
1	0	1	1
1	1	X	No Chg
1		D	d
d = state of input one setup time prior to Low-to-High gate transition