TLK3118 Datasheet, PDF (13/57 Pages) Texas Instruments – Redundant XAUI Transceiver

www.ti.com
RESET
UNALIGN
De-skew
Error
Valid
Data
FAIL3
De-skew
Error
Valid
Data
FAIL2
TLK3118
Redundant XAUI Transceiver
SLLS628A – DECEMBER 2004 – REVISED APRIL 2005
De-skew
Error
Valid
Data
FAIL1
||A||
DET1
Valid
Data
||A||
De-skew
De-skew
De-skew _Error
Error
Error
DET2
||A||
||A||
Valid
Data
||A||
De-skew
||A||
Error
DET3
||A||
Valid
Data
ALIGN
Valid
Data
Figure 12. Column De-Skew State Machine
Column State Descriptions
UNALIGN
This is the initial state for the column state machine upon device power up or reset. If any of the channel state
machines are set to UNSYNC, the column state is set to UNALIGN. In this state, the column state machine will
search for alignment character codes (K28.3 or /A/) on each channel and align the FIFO pointers on each
channel to the /A/ character code. While in this state, the Column Alignment Sync bit is set to '0' in MDIO
registers 4:5.24.12, indicating the column is not aligned. The column state will transition to the DET1 state upon
the detection and alignment of /A/ character codes in all four channels.
DET1
During this state, the alignment character code detect circuit is active on each channel but the column
re-alignment is disabled. The column state machine will remain in this state looking for a column of alignment
character codes. If an incomplete alignment column is detected (alignment character codes not found on all
channels) or a deskew error is detected, the column state machine will transition to state UNALIGN. While in this
state, the Column Alignment Sync bit is set to '0' in MDIO registers 4:5.24.12 indicating the column is not aligned.
Detection of a complete alignment column will cause the column state machine to transition to state DET2.
NOTE:
The XGXS Lane Alignment bit = '0' will cause a local fault to be output on the receive
data bus.
DET2
During this state, the alignment character code detect circuit is active on each channel but the column
re-alignment is disabled. The column state machine will remain in this state looking for a column of alignment
character codes. If an incomplete alignment column is detected (alignment character codes not found on all
channels) or a deskew error is detected, the column state machine will transition to state UNALIGN. While in this
state, the Column Alignment Sync bit is set to '0' in MDIO registers 4:5.24.12 indicating the column is not aligned.
Detection of a complete alignment column will cause the column state machine to transition to state DET3.
NOTE:
The XGXS Lane Alignment bit = '0' will cause a local fault to be output on the receive
data bus.
13