AD9992BBCZ datasheet(36/92 Pages) AD

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AD9992

Rev. C | Page 36 of 92

Vertical Masking Using FREEZE/RESUME Registers

As shown in Figure 43 and Figure 44, the FREEZE/RESUME

registers are used to temporarily mask the V-outputs. The pixel

locations to begin the masking (FREEZE) and end the masking

(RESUME) create an area in which the vertical toggle positions

are ignored. At the pixel location specified in the FREEZE register,

the V-outputs are held static at their current dc state, high or low.

The V-outputs are held until the pixel location that is specified

by the RESUME register is reached, at which point the signals

continue with any remaining toggle positions, if any exist.

Four sets of FREEZE/RESUME registers are provided, allowing the

vertical outputs to be interrupted up to four times in the same line.

The FREEZE and RESUME Position 1 to Position 4 are enabled

independently and applied to all groups (Group A, Group B, Group

C, and Group D) using the VMASK_EN register.

Note that when masking is enabled, Group A, Group B, Group C,

and Group D use the same FREEZE/RESUME positions.

Note that the FREEZE/RESUME registers are also used as the

VALTSEL0 and VALTSEL1 registers during special vertical

alternation mode.

XV1

XV24

NO MASKING AREA

Figure 43. No FREEZE/RESUME

XV1

XV24

V-MASKING AREA

FREEZE

RESUME

NOTES

1. ALL TOGGLE POSITIONS WITHIN THE FREEZE/RESUME MASKING AREA ARE IGNORED. H-COUNTER CONTINUES TO COUNT DURING MASKING.

2. FOUR SEPARATE MASKING AREAS ARE AVAILABLE, USING FREEZE1/RESUME1, FREEZE2/RESUME2, FREEZE3/RESUME3, AND

FREEZE4/RESUME4 REGISTERS.

Figure 44. Using FREEZE/RESUME

AD9992BBCZ Datasheet(PDF) 36 Page - Analog Devices