AK8813 Datasheet, PDF (26/51 Pages) Asahi Kasei Microsystems – NTSC/PAL Digital Video Encoder

ASAHIKASEI
[AK8813/14]
♦ AK8813/14 Interface Timing (Part 2) Slave mode
On slave mode operation, HSYNC and FID or VSYNC (Selected by register) are input to AK8813/14.
AK8813/14 monitors the transition of HSYNC at the timing of the rising edge of SYSCLK. (Refer to AC
Characteristic 2-1. [Input Synchronizing Signal]) After AK8813/14 recognizes HSYNC is Low-logic,
AK8813/14 sets the slot number to the 32nd/24th(NTSC/PAL), internally, then AK8813/14 starts to sample
the data as Cb on 276th/288th(NTSC/PAL) slot.
Video field is recognized the transition timing between FID/VSYNC and HSYNC. (Fig.10. Video Field) As
in the figure, there is a tolerance of ±1/4H.
27MHz
Data
HSYNC
244T / 264T (525/625)
Cb₀
Y₀
Cr₀
Y₁
Cb₁
Y₂
Cr₁
TBD-clk
HSYNC
Start of 1st Field
VSYNC/FIELD
Start of 2nd Field
VSYNC/FIELD
Fig. 11 Interfacing timing (Slave mode)
1/2 H 1/2 H
1/4 H1/4 H
1/4 H 1/4 H
Fig. 12 Video Field
Rev.00
- 27 -
2004/Oct