AD9927BBCZ datasheet(38/100 Pages) AD

38 / 100 page

AD9927

Rev. 0 | Page 38 of 100

Vertical Masking Using FREEZE/RESUME Registers

As shown in Figure 44 and Figure 45, 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 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 Positions 1 to 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, each group (Group A,

Group B, Group C, and Group D) uses 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 44. 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 45. Using FREEZE/RESUME

AD9927BBCZ датащи(PDF) 38 Page - Analog Devices