Datasheet

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SLLS428F − JUNE 2000 − REVISED JANUARY 2004
12
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synchronization and initialization (continued)
4 Consecutive Valid Code Words Received
Power-Up/Reset
Invalid Code
Word Received
ACQ
(Link Acquisition)
3 Invalid Code
Words Received
Loss of Link
Link in Question
1 Invalid Code
Word Received
CHECK
(Look for Valid Code)
Link Re-established
SYNC
(Normal Operation)
Link Established
3 Consecutive Valid IDLEs or Carrier Extends,
or
1 Valid Data or Error Propagation
Valid Code
Word Received
Figure 6. Initialization and Synchronization State Diagram
If during normal transmission and reception, an invalid code is received, the TLK1501 notifies the attached
system or protocol device as described in comma detect and 8-bit/10-bit decoding. The synchronization state
machine transitions to the CHECK state. The CHECK state determines whether the invalid code received was
caused by a spurious event or a loss of the link. If, in the CHECK state, the decoder sees four consecutive valid
codes, the state machine determines the link is good and transitions back to the SYNC state for normal
operation. If, in the CHECK state, the decoder sees three invalid codes (not required to be consecutive), the
TLK1501 determines a loss of the link has occurred and transitions the synchronization-state machine back to
the link-acquisition state (ACQ).
The state of the transmit data bus, control terminals, and serial outputs during the link acquisition process is
illustrated in Figure 7.
ACQ
D0−D15
DOUTTXP,
DOUTTXN
TXD[0−15]
TX_ER
Ca. Ext.
Error
IDLE
SYNC
TX_EN
D0−D15
xx xx xx xxxxxxxx
xx xx xx xx xx xx xx
xx xxxxxxxx xx xx xx
Figure 7. Transmit Side Timing Diagram