ak8825 AKM Semiconductor, Inc., ak8825 Datasheet - Page 114

• Manufacturer Part Number: ak8825
• Description: Hd/sd Multi Format Video Encoder With 3ch Dac
• Manufacturer: AKM Semiconductor, Inc.

(2) Slave mode
Low-logic, AK8825 sets the slot number to the 32nd/24th (NTSC/PAL), internally, then AK8825 starts to sample the data as Cb
on 276th/288th (NTSC/PAL) slot.
This interface mode is set by REC656-bit =0 of SD Blanking Set Register (R/W) [Sub Address 0x10] .
Field Detection with HSYNC and VSYNC
Rev-E-00
Video field is recognized the transition timing between VSYNC and HSYNC. As in the figure, there is a tolerance of ± 1/4H.
On slave mode operation, HSYNC and VSYNC are input to AK8825.
AK8825 monitors the transition of HSYNC at the timing of the rising edge of SYSCLK. After AK8825 recognizes HSYNC is
27MHz
Data
HDI
HDI
2nd Field
1st Field
VDI
VDI
244T / 264T (525/625)
1/4 H
Fig. 156 Relation between HSYNC and Data
1/4 H
1/2 H
1/4 H 1/4 H
Fig. 157
1/2 H
HD/VD timing
114
Cb
0
Y
0
Cr
0
Y
1
Cb
1
Y
2
Cr
1
2008/03
[AK8825]