TLK3101_16 Datasheet, PDF (9/28 Pages) Texas Instruments – 2.5 Gbps to 3.125 Gbps TRANSCEIVER

TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649B − AUGUST 2000 − REVISED JANUARY 2008
receive interface (continued)
power down mode
When the ENABLE pin is deasserted low, the TLK3101 will go into a power down mode. In the power down
mode, the serial transmit pins (DOUTTXP, DOUTTXN), the receive data bus pins (RXD[0:15]), and RX_ER will
go into a high-impedance state. In the power-down mode the RX_DV/LOS pin acts as an output of the signal
detection circuit which remains active. If the signal detection circuit detects a valid differential signal amplitude
of >200 mV on each of the serial receive pins (DINRXP, DINRXN), RX_DV/LOS is driven high. If no signal of
sufficient amplitude is detected, the signal detection circuit will indicate a loss of signal by driving RX_DV/LOS
low. In the power-down condition, the signal detection circuit draws less than 5 mW.
synchronization and initialization
The TLK3101 has a synchronization state machine which is responsible for handling link initialization and
synchronization. Upon power up or reset, the state machine enters the acquisition (ACQ) state and searches
for IDLE. Upon receiving three consecutive IDLEs or carrier extends, the state machine will enter the
synchronization (SYNC) state. If, during the acquisition process, the state machine receives valid data or an
error propagation code, it will immediately transition to the SYNC state. The SYNC state is the state for normal
device transmission and reception. The initialization and synchronization state diagram is provided in Figure 6.
Invalid Code
Word Received
Power-Up/Reset
3 Invalid Code
Words Received
ACQ
(Link Acquisition)
3 Consecutive Valid IDLEs or Carrier Extends,
or
1 Valid Data or Error Propagation
Loss of Link
Link Established
Valid Code
Word Received
CHECK
(Look for Valid Code)
1 Invalid Code
Word Received
Link in Question
SYNC
(Normal Operation)
Link Re-established
4 Consecutive Valid Code Words Received
Figure 6. Initialization and Synchronization State Diagram
If, during normal transmission and reception, an invalid code is received, the TLK3101 will notify the attached
system or protocol device as described in comma detect and 8-b/10-b decoding. The synchronization state
machine will transition to the CHECK state. The CHECK state will determine 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 4 consecutive
valid codes, the state machine will determine the link is good and transition 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
TLK3101 will determine a loss of the link has occurred and transition the synchronization state machine back
to the link acquisition state (ACQ).
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