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Theory of Operation
X64-AN Quad User's Manual
WEN
Some cameras indicate when valid data is output by generating a write enable signal (WEN). The
function of WEN is similar to a vertical sync pulse. When enabled, the X64-AN Quad uses WEN as
the vertical timing reference instead of VS. Some cameras generate WEN, but with no VS pulse
embedded in the composite video signal.
Frame Reset
WEN
HD
Video Out
Integrated Video
Figure 20: WEN Timing
One WEN signal is available per connected camera. WEN has programmable polarity; it can be
selected to be active high or active low.
Sapera parameters for WEN :
CORACQ_PRM_WEN_ENABLE = {TRUE, FALSE}
CORACQ_PRM_WEN_POLARITY = { CORACQ_VAL_ACTIVE_LOW,
CORACQ_VAL_ACTIVE_HIGH}
CORACQ_PRM_VBACK_INVALID: Number of lines to skip for valid video after
WEN pulse
