Datasheet

AD9920A
Rev. B | Page 85 of 112
VERTICAL TOGGLE POSITION PLACEMENT NEAR
COUNTER RESET
An additional consideration during the reset of the internal
counters is the vertical toggle position placement. There is a
region of 36 pixels prior to the internal counter reset in which
no toggles can take place.
Figure 107 shows this restriction for slave mode. The last 36 pixels
before the counters are reset cannot be used. In slave mode, the
counter reset is delayed with respect to VD/HD placement, so
the inhibited area is different than it is in master mode.
It is recommended that Pixel Location 0 not be used for any of
the toggle positions for the VSG and SUBCK pulses.
06878-107
N-1N012
VD
HD
N-2N-3N-4
NO TOGGLE POSITIONSALLOWED IN THIS AREA
N-5N-6N-7N-8N-9N-10N-11N-12N-13N-32N-33N-34N-35XXXXXX
NOTE:
TOGGLE POSITIONS CANNOT BE PROGRAMMED WITHIN 36 PIXELS OF PIXEL 0 LOCATION.
H-COUNTER
(PIXEL COUNTER)
H-COUNTER
RESET
Figure 107. Toggle Position Inhibited Area, Slave Mode