Datasheet

AD9920A
Rev. B | Page 42 of 112
Hold Area Using the FREEZE/RESUME Registers
The FREEZE/RESUME registers can also be used to create a
hold area in which the V-outputs are temporarily held and later
continued, starting at the point where they were held. As shown
in Figure 53, the hold area function is different from the vertical
masking function in that the V-outputs continue from where
they stopped rather than continuing from where they would
have been. The hold area temporarily stops the pixel counter
for the V-outputs, whereas vertical masking allows the counter
to continue in the masking area.
XV1
XV8
HD
NOTES
1. WHEN HOLD = 1 FOR ANY V-SEQUENCE GROUP, THE FREEZE AND RESUME REGISTERS ARE USED TO SPECIFY THE HOLD AREA.
2. IN THIS EXAMPLE, XV1 TO XV10 ARE ASSIGNED TO GROUP A. HOLD BIT FOR GROUP A = 1.
3. H-COUNTER FOR GROUP A (XV1 TO XV10) STOPS DURING HOLD AREA.
XV9
HOLD AREA
FOR GROUP A
X
V10
FREEZE
RESUME
0
6878-052
Figure 53. Hold Area for Group A