THC7984_15 Datasheet, PDF (36/46 Pages) THine Electronics, Inc. – 10-bit 3-channel Video Signal Digitizer

THC7984_Rev.2.0_E
*About timing of input VSYNC
Input VSYNC Forbidden Region
0%
15%
35%
Input HSYNC
Input VSYNC
65%
85% 100%
Input VSYNC Forbidden Region
When the transition of VSYNC is in “Input VSYNC Forbidden Region”, it is possible that following vertical timing fluc-
tuates about one line.
VSYNC output (VO, Regenerated VSYNC) ---Setting Register: R20[6:0]/R21[5:0]
PLL COAST Timing ---Setting Register: R22[6:0]/R23[6:0]
Clamp COAST Timing ---Setting Register: R24[6:0]/R25[6:0]
DE Restraint period ---Setting Register: R2A[6:0]/R2B[6:0]
The edge of Input VSYNC must be outside "Input VSYNC Forbidden Region" to prevent fluctuation of these vertical
timing.
R20[7] VSYNC Output (VO, Regenerated VSYNC) Timing Automatic Setting Enable
When set to 1, VSYNC Output Start Position (R20[6:0]) and VSYNC Output Pulse Width (R21[5:0]) are automatically
set to match the VSYNC input timing. The VSYNC Output Start Position is set to 0 and the VSYNC Output Pulse Width
is determined by sync processor based on the result of VSYNC Input Pulse Width Measurement (R2F[7:0]).
R20[6:0] VSYNC Output (VO, Regenerated VSYNC) Start Position
The starting position of VO and Regenerated VSYNC, which are the possible output from VSOUT-pin, is set in steps of
1 line based on leading edge of Input VSYNC. The set value is expressed by complement of 2 and the set range is from -
64 to +63.
R21[5:0] VSYNC Output (VO, Regenerated VSYNC) Pulse Width
The pulse width of VO and Regenerated VSYNC, which are the possible output from VSOUT-pin, is set in steps of 1
line.
< Output VSYNC Start Position / Pulse Width >
Horizontal Period
Input VSYNC
Output VSYNC
(R20[6:0]= -1)
Output VSYNC
(R20[6:0]= 0)
Output VSYNC
(R20[6:0]= +1)
Output VSYNC Pulse Width
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