tea5766uk NXP Semiconductors, tea5766uk Datasheet - Page 25

• Manufacturer Part Number: tea5766uk
• Description: Tea5766uk Stereo Fm Radio + Rds
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TEA5766UK_1
Product data sheet
9.2 DAV-B processing mode and fast PI search mode
This mode is used when, for example, the receiver has been re-tuned to a new station and
a fast search of the PI code (always contained in the A/C’-block) is required. The diagram
shown in
performing a synchronization search.
During synchronization search the decoder does not set the DAVFLG until a valid
A/C’-block is detected. If a valid B-block is immediately detected, the decoder is
synchronized and the SYNC bit is set to logic 1. In fact, if any 2 good blocks in a valid
order are found the RDS decoder will synchronize and give an interrupt.
If for some reason a valid B block was not received the next valid A/C’-block is decoded
and the DAVFLG set. The BP and BL registers would record the A-block history.
After synchronization each decoded block will set the DAVFLG (assuming it was reset by
a read action) and generate an interrupt.
Fig 10. DAV-B timing diagram
Bus access - read
BBG = 3: synchronization is reached after receiving 1 good block and after 0, 1 or 2 bad blocks
and again a good block. After three bad blocks there will be no synchronization and the
counters will be reset waiting for a new good block.
Figure
only valid blocks with no errors
SYNC status bit
are counted as good blocks
BL register
BP register
DAVFLG
10, assumes that the RDS decoder is unsynchronized initially and is
bad
B
INTX
good A or C' block detected
1
read INTMSK
Rev. 01 — 22 March 2007
21.9 ms
good
C'
x
x
1
bad
C'
D
x
1
1
not synchronized
read BL register
bad
C'
A
x
error correction applied
2
according to SYM bits
1
good
C'
B
x
2
1
TEA5766UK
Stereo FM radio + RDS
good
C'
B
C
2
1
2
synchronized
© NXP B.V. 2007. All rights reserved.
C
B
001aaf588
2
2
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