THC7984 Datasheet, PDF (36/45 Pages) THine Electronics, Inc. – 10-bit 3-channel Video Signal Digitizer

THC7984_Rev.2.0_E
R22[7] PLL COAST Timing Automatic Setting Enable
PLL should stop synchronization with the HSYNC input during the vertical blank time including the pulses disturbing
PLL lock and the sampling clock generation such as equalization pulses and copy protection signal. PLL COAST signal
causes PLL to stop synchronization with the HSYNC input and free-run.
1: PLL Pre-COAST (R22[6:0]) and PLL Post-COAST (R23[6:0]) are automatically set
PLL COAST Period generated by automatic setting is depend on the setting of PLL HSYNC Filter Enable (R1F[4]) .
* When HSYNC Filter is disabled (R1F[4]=0) , the PLL COAST period covers the period including extraneous and
missing pulses in vertical blank time.
* Even in the case Input Sync Type is set to “Separate Sync” (R12[1:0]=00b) , the PLL COAST signal covers the
VSYNC pulse period.
* When HSYNC Filter is enabled (R1F[4]=1) , the PLL COAST period covers the VSYNC pulse period because
extraneous pulses are eliminated by HSYNC Filter.
< PLL COAST Auto Mode>
Horizontal Period
Input HSYNC
HSYNC Filter Disable (R1F[4]=0)
Raw HSYNC
PLL COAST
HSYNC Filter Enable (R1F[4]=1)
Filtered HSYNC
PLL COAST
R22[6:0] PLL Pre-COAST
Set the start position of PLL COAST in steps of 1 line with reference to the leading edge of the VSYNC input.
R23[6:0] PLL Post-COAST
Set the end position of PLL COAST in steps of 1 line with reference to the leading edge of the VSYNC input.
< PLL COAST Timing>
Horizontal Period
Input VSYNC
PLL COAST
PLL Pre-COAST
PLL Post-COAST
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