AK8856 Datasheet, PDF (83/105 Pages) Asahi Kasei Microsystems – NTSC/PAL Digital Video Decoder

ASAHI KASEI
[ AK8856 ]
No Input Signal Condition
Two output modes can be selected when no Video signal is input to the AK8856. The default value is Black code
output. This is set by the NSIGMD-bit of Output Control 2 Register (R/W) [Sub Address 0x02]. Detection of a
no signal condition is indicated by a hardware pin and the Status Register (R / W) [Sub Address 0x10].
[NSIGMD] bit
This sets the output signal when no input signal is detected.
[NSIGMD]-bit
Output signal when no signal is input
00
Black code output
01
Blue back output
10
Input signal is directly output as is.
11
Reserved
Condition
Y = 0x10
Cb/Cr = 0x80
So-called “ Sand-Storm “ mode output.
Power-Down Mode
The AK8856 has a power-saving wait mode function. The PDN pin is used to put the AK8856 into power-saving
mode, including the digital block. By setting this pin low, all blocks in the analog and digital blocks are put into
power-saving mode. After recovering from power-saving mode by resetting the PDN pin, a reset sequence must
be executed.
When reducing power supplies (except PVDD), a power-down sequence must be followed by setting the PDN
pin and then reducing AVDD and DVDD after the power-down condition is established. During power-down
mode, digital output pins should be tied to the PVDD power supply, or set the OE pin = high (high output).
Output Pin Condition
Output pins of the AK8856 are controlled by the OE (Output Enable) pin and RSTN pin conditions.
Output pin conditions:
OE = High
OE = Low
After Power up
unknown
Hi-z
RSTN = Low
Hi-z
Hi-z
After Reset Sequence
PDN = Low
PDN = High
High
Data output
Hi-z
Hi-z
Rev-01
83
2007/03