AK8825 Datasheet, PDF (29/162 Pages) Asahi Kasei Microsystems – HD/SD Multi Format Video Encoder with 3ch DAC

Mode switching sequence
(1) Component Video Encoder mode to Composite Video Encoder mode
Component Video Encoder mode Composite Video Encoder mode
CONVMOD[1:0]-bit (r)
Register Setting (r)
DTRSTN-bit (r)
DACnEN-bit (r)
PLLPDN-bit (r)
HDBBG-bit (r)
Data Input
CLKIN
0x00
(6)
(7)
0x01
(9)
(2)
(10)
(4)
PLL is Power Down State
(1)
(3)
Input
Low or High
(5)
(8)
Low or High
t >30ms
t >100clk
Input
[AK8825]
Fig. 21 Mode Switching sequence (Component Video Encoder mode to Composite Video Encoder mode)
(1) To avoid making noise, Black Burst Generator is On, then stop inputting data.
(2) Turn Off DACs.
(3) Black Burst Generator OFF.
(4) Set PLLPDN-bit = 0 (PLL Block becomes Power Down States)
(5) Stop Clock Input to CLKIN pin.
(6) Mode Change from Componet VIdeo Encoder mode to Composite Video Encoder mode.
(7) Set Sync-mode, Output Signal etc.
(8) Chang clock, if necessary.
It is allows that changing clock without stopping clock input, however Process(6), (7) should
be done before clock change.
(9) Set DTRSTN=1 after DTRSTN-bit =0.
DTRSTN-bit =0 periode should be more than 100-clk counts with clock input.
(10) Turn On DACs after more than 30ms later
Rev-E-00
29
2008/03