ak8825 AKM Semiconductor, Inc., ak8825 Datasheet - Page 31

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

(3) Clock rate change in Component Video Encoder mode
Rev-E-00
Fig.23 shows the sequence of Clock rate is changed from 27MHz to 74.25MHz or 74.25MHz to 27MHz.
HDMOD[1:0]-bit (r)
(1) To avoid making noise, Black Burst Generator is On, then stop inputting data.
(2) Turns Off DACs
(3) Black Burst Generator OFF.
(4) Set PLLPDN-bit = 0 (PLL Block becomes Power Down States)
(5) Mode Change, for example, from D1 to D3.
(6) Chang clock
(7) Turning on PLL (Set PLLPDN-bit = 1)
(8) After PLL becomes stable, starting input video data.
(9) Turn ON DACs after more than 30ms later
DACnEN-bit (r)
PLLPDN-bit (r)
It is allows that changing clock without stopping clock input, however, PLLPDN-bit should be 0.
HDBB-bit (r)
Fig. 23 Clock rate change in Component Video Encoder mode
Data input
CLKIN
27MHz / 74.25MHz
27MHz / 74.25MHz mode
(1)
Input
D1 or D2 / D3 or D4
(2)
(3)
Low or High
(4)
31
Low or High
(5)
t > 1ms
(6)
74.25MHz / 27MHz mode
(7)
D3 or D4 / D1 or D2
(8)
74.25MHz / 27MHz
(9)
t>1Frm
Input
2008/03
[AK8825]