AK8855 Datasheet, PDF (27/81 Pages) Asahi Kasei Microsystems – NTSC/PAL Digital Video Decoder

[ASAHI KASEI]
When to read out VBID Data :
AK8855
Write “1” to VBWSRQ-bit of Request VBI Info Register ( W ) [ Sub Address 0x0A ].
When “1” is written to this bit, the AK8855 is put into a wait condition for VBID data decoding.
Then when data comes in, it is decoded and after the decoding, “1” is written back to VBWSDET-bit of Status
Register ( R / W ) [ Sub Address 0x10 ].
VBWSDET-bit right after reset, is “1” ( it becomes “0” when “1” is written to VBWSRQ-bit ).
Decoded data is 13 Bit-long and it is written into VBID / WSS1 Register ( R ) [ Sub Address 0x16 ] and VBID /
WSS 2 Register ( R ) [ Sub Address 0x17 ].
VBID data is valid only in 525 Line system. These registers are also commonly used for WSS Read-Out
register.
CRCC code is decoded and its data only is stored in register.
Data in VBID / WSS 1 Register and VBID / WSS 2 Register are retained till they are over-written with new
data.
Configuration of VBID / WSS 1 Register and VBID / WSS 2 Register are as follow.
VBID/WSS 1 Register (R) [Sub Address 0x16]
Sub Address 0x16
bit 7
bit 6
bit 5
bit 4
Reserved Reserved VBID1
VBID2
Register to store VBID data
bit 3
VBID3
bit 2
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
When to read out WSS Data :
Write “1” to VBWSRQ-bit of Request VBI Info Register ( W ) [ Sub Address 0x0A ].
When “1” is written to this bit, the AK8855 is put into a wait condition for VBWS data decoding.
Then when data comes in, it is decoded and after the decoding, “1” is written back to VBWS-bit of Status
Register ( R / W ) [ Sub Address 0x10 ].
VBWS-bit right after reset, is “1” ( it becomes “0” when “1” is written to VBWSRQ-bit ).
WSS data is valid only in 625 Line system.
These registers are also commonly used for VBID Read-Out register.
Decoded results are written into VBID / WSS 1 Register ( R ) [ Sub Address 0x16 ] and VBID / WSS 2
Register ( R ) [ Sub Address 0x17 ] as shown next.
Data in VBID / WSS 1 Register and VBID / WSS 2 Register are retained till they are over-written with new
data.
VBID/WSS 1 Register (R) [Sub Address 0x16] Register to store 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 to store 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
MS0319-E-03
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