Test Pattern Generation
A self-test pattern signal comes out from pin PB3/PAT. It can generate a cross hatch picture, a inverted
cross hatch picture, a whit epicture or a black picture.
8
×
8 cross hatch Inverted 8
×
8 cross hatch
White Picture Black Picture
The test pattern signal is generated when SELF and ENPAT are both set to “1”. This video signal will
synchronize to the free-running Hsync and Vsync, no matter which frequency is chosen. The following
diagram shows the timing relationship of cross hatch picture.
HSO
PAT
T
1
T
2
T
1
T
3
T
2
HSO VSO T
1
T
2
T
3
31.1kHz 60.8Hz 6us 1us 62.5ns
47.9kHz 74.9Hz 5.125us 0.625us 62.5ns
64kHz 62.5Hz 3.625us 0.875us 62.5ns
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