Datasheet

AD9923A
Rev. A | Page 31 of 84
Hold Area Using FREEZE/RESUME Registers
The FREEZE/RESUME registers can also be used to create a
hold area, in which the XV outputs are temporarily held and
then later resume at the point where they were held. As shown
in Figure 44, this is different than using the VMASK register,
because the XV outputs continue from where they stopped (as
opposed to having the pixel counter run continuously), with
any toggle positions that fall between the FREEZE and
RESUME locations being ignored. Signals assigned to Group B
are not affected by the hold area.
XV1
X
V11
HD
NOTES
1. WHEN HOLD = 1 FOR ANY V-SEQUENCE, THE FREEZE AND RESUME REGISTERS ARE USED TO SPECIFY THE HOLD AREA FOR GROUP A.
2. ABOVE EXAMPLE: ALL XV-OUTPUTS ARE ASSIGNED TO GROUP A.
3. H-COUNTER FOR GROUP A (XV1 TO XV13) STOPS DURING HOLD AREA.
X
V12
HOLD AREA
FOR GROUP A
X
V13
FREEZE RESUME
05586-043
Figure 44. Hold Area for Group A
XV1
X
V11
HD
NOTES
1. ABOVE EXAMPLES: XV12 AND XV13 ARE ASSIGNED TO GROUP B.
2. GROUP B DOES NOT USE HOLD AREA.
X
V12
HOLD AREA
FOR GROUP A
X
V13
NO HOLD
AREA FOR
GROUP B
FREEZE
RESUME
05586-044
Figure 45. Group B Does Not Use Hold Area