AK8826 Datasheet, PDF (110/157 Pages) Asahi Kasei Microsystems – HD/SD Multi Format Video Encoder with 3ch DAC

(2) Slave mode
On slave mode operation, HSYNC and VSYNC are input to AK8826.
[AK8826VN]
AK8826 monitors the transition of HSYNC at the timing of the rising edge of SYSCLK. After AK8826 recognizes HSYNC is
Low-logic, AK8826 sets the slot number to the 32nd/24th (NTSC/PAL), internally, then AK8826 starts to sample the data as Cb
on 276th/288th (NTSC/PAL) slot.
Video field is recognized the transition timing between VSYNC and HSYNC. As in the figure, there is a tolerance of ±1/4H.
This interface mode is set by REC656-bit =0 of SD Blanking Set Register (R/W) [Sub Address 0x10].
244T / 264T (525/625)
27MHz
Data
HDI
Cb₀
Y₀
Cr₀
Y₁
Cb₁
Y₂
Cr₁
Fig. 155 Relation between HSYNC and Data
Field Detection with HSYNC and VSYNC
1/2 H 1/2 H
HDI
1st Field
VDI
2nd Field
VDI
1/4 H 1/4 H
1/4 H 1/4 H
Fig. 156 HD/VD timing
MS0972-E-01
110
2008/12