AK8811_12 Datasheet, PDF (21/36 Pages) Asahi Kasei Microsystems – NTSC/PAL Digital Video Encoder

ASAHI KASEI
[AK8811/12]
♦ AK8811/12 Interface Timing (Part 1) Master mode & ITU-R BT. 656 mode
On ITU-R BT.656 decoding mode or master mode operation, AK8811/12 outputs HSYNC
and FID or VSYNC (selected by register).
When AK8811/12 receives ITU-R BT. 656 signal, AK8811/12 decodes [EAV] code in the data
for synchronization then outputs the HSYNC. AK8811/12 outputs HSYNC at the rising edge
of SYSCLK in the timing of the 32nd/24th(NTSC/PAL) data slot, which is counted from the
[EAV] starting point as below. (See also AC Characteristics 2-2[Input Synchronizing Signal])
On master mode operation, the front device connected with AK8811/12 (ex. MPEG Decoder)
starts to set Cb on the 276th/288th(NTSC/PAL) slot, after starting to count HSYNC falling
edge as 32nd/24th(NTSC/PAL) slot.
FID/VSYNC is output synchronously with HSYNC at the timing of solid line as in Fig. 10
Video Field.
244T
(264T)
Cb Y Cr Y
ITU-R. BT601(656)
HSYNC
27MHz SYSCLK
32
(24)
276
(288)
NTSC(PAL)
T=1/27MHz
* Uncertainty of 1T occurs
according to the Reset
timing.
Fig. 8 Interface Timing (ITU-R BT.656 or Master mode)
Rev.1.1
21
2000/01