TEA5764UK/N2,027 NXP Semiconductors, TEA5764UK/N2,027 Datasheet - Page 29

• Manufacturer Part Number: TEA5764UK/N2,027
• Description: Tuners FM RADIO WITH RDS
• Manufacturer: NXP Semiconductors

Specifications of TEA5764UK/N2,027

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 935278071027 TEA5764UK-G

Philips Semiconductors
TEA5764UK_2
Product data sheet
10.4.1 Conditions for synchronization
10.4 Synchronization
When the RDS decoder is turned on it must be synchronized to extract valid data from the
MPX signal. To do so the decoder automatically initiates a search for synchronization. The
conditions to meet synchronization and the status of this synchronization can be set and
checked by the following bits:
When the decoder is not synchronized it will initiate a synchronization search. This
involves calculation of the syndrome for each block of 26 received bits on a bit-by-bit
basis. When a correct syndrome (and hence block ID) is received the decoder clocks the
next 26 bits into the internal registers and performs a second syndrome check.
Synchronization is found when a certain number of blocks have been decoded and two
good blocks have been found, this number of blocks is defined by the BBG bits. If the first
block needed for synchronization has been found and the expected second block (after
26 bits) is an invalid block, then the decoder module internal bad_blocks_counter is
incremented and the next expected block is calculated; exception: if RBDS mode is
selected and the first block is E, then the next expected block is always block A, until
synchronization is found or the maximum bad_blocks_counter value is reached. If the
decoder module internal bad_blocks_counter reaches the value of BBG[4:0], then a new
synchronization search (bit-by-bit) is started immediately to find a new first block.
The synchronization is monitored by two flywheel counters, GBC and BBC. These are
6-bit counters that can be preset by bits GBL and BBL to values between 0 and 63. Each
time a block is decoded and recognized as a bad block the Bad Block Counter value,
BBC, is incremented by 1. When the BBC value is equal to the BBL value, synchronization
is lost. Bit SYNC will become 0 and bit LSYNCFL is set to indicate the loss of
synchronization. The TEA5764UK will now automatically initiate a new synchronization
search.
Each time a good block is decoded, the GBC value is incremented. When the GBC value
is equal to the GBL value, both counters, BBC and GBC, are set to 0 and a new count
starts. The GBC counter is only incremented when the decoder is synchronized.
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BBL (Bad Blocks Lose): these bits can be set via the I
between 0 to 63
GBL (Good Blocks Lose): these bits can be set via the I
between 0 to 63
BBG (Bad Blocks Gain): these bits can be set via the I
between 0 to 32
GBC (Good Block Count): these bits can be read via the I
between 0 to 63
BBC (Bad Block Count): these bits can be read via the I
between 0 to 63
Rev. 02 — 9 August 2005
2
2
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
C-bus and have a value
C-bus and have a value
2
2
C-bus and have a value
C-bus and have a value
2
C-bus and have a value
TEA5764UK
FM radio + RDS
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