AK8856 Datasheet, PDF (41/105 Pages) Asahi Kasei Microsystems – NTSC/PAL Digital Video Decoder

ASAHI KASEI
[ AK8856 ]
Reading out VBID Data :
Write a “1” to the VBWSRQ-bit of the Request VBI Info Register (W) [Sub Address 0x0A]. When a “1” is
written to this bit, the AK8856 is placed in a wait condition for VBID data decoding. Then when data arrives, it
is decoded and a “1” is written to the VBWSDET-bit of the Status Register (R / W) [Sub Address 0x10 ].
After reset, the VBWSDET-bit is a “1” (it goes to “0” when a “1” is written to the VBWSRQ-bit). Decoded data
is 13-bits long, and it is written into the VBID / WSS1 Register ( R ) [ Sub Address 0x16 ] and VBID / WSS
2 Register ( R ) [ Sub Address 0x17 ]. VBID data is valid only in a 525-line system. These registers are also
commonly used for WSS Read-Out register.
CRCC code is decoded and the result is stored in the register. Data in the VBID / WSS 1 Register and VBID
/ WSS 2 Register are retained until they are over-written with new data.
Configuration of VBID / WSS 1 Register and VBID / WSS 2 Register:
VBID/WSS 1 Register (R) [Sub Address 0x16] Register to store VBID data
Sub Address 0x16
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
Reserved Reserved
VBID1
VBID2
VBID3
VBID4
bit 1
VBID5
bit 0
VBID6
VBID/WSS 2 Register (R) [Sub Address 0x17] Register to store VBID data
Sub Address 0x17
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
VBID7
VBID8
VBID9
VBID10
VBID11
VBID12
bit 1
VBID13
bit 0
VBID14
Reading out WSS Data :
Write a “1” to the VBWSRQ-bit of the Request VBI Info Register (W) [Sub Address 0x0A]. When a “1” is
written to this bit, the AK8856 is placed in a wait condition for VBWS data decoding. Then when data arrives,
it is decoded and a “1” is written back to the VBWS-bit of Status Register (R / W) [Sub Address 0x10].
After reset, the VBWS-bit is a “1” (it goes to “0” when a “1” is written to the VBWSRQ-bit). WSS data is valid
only for 625-line systems. These registers are also commonly used for VBID Read-Out register. Decoded
data are written into the VBID / WSS 1 Register (R) [Sub Address 0x16] and the VBID / WSS 2 Register
(R) [Sub Address 0x17]. Data in the VBID / WSS 1 Register and the VBID / WSS 2 Register are retained
until they are over-written with new data.
VBID/WSS 1 Register (R) [Sub Address 0x16] Register for storing WSS data
Sub Address 0x16
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
Reserved Reserved
G4-13
G4-12
G4-11
G3-10
bit 1
G3-9
bit 0
G3-8
VBID/WSS 2 Register (R) [Sub Address 0x17] Register for storing WSS data
Sub Address 0x17
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
G2-7
G2-6
G2-5
G2-4
G1-3
G1-2
bit 1
G1-1
bit 0
G1-0
Rev-01
41
2007/03