220.127.116.11.2. Word Aligner Manual Mode
In manual alignment mode, the word aligner operation is controlled by rx_std_wa_patternalign. The word aligner operation is edge-sensitive or level-sensitive to rx_std_wa_patternalign, depending upon the PCS-PMA interface width selected.
|PCS-PMA Interface Width||rx_std_wa_patternalign Behavior|
|8||Rising edge sensitive|
|16||Rising edge sensitive|
|20||Rising edge sensitive|
If rx_std_wa_patternalign is asserted, the word aligner looks for the programmed word alignment pattern in the received data stream. It updates the word boundary if it finds the word alignment pattern in a new word boundary. If rx_std_wa_patternalign is deasserted, the word aligner maintains the current word boundary even when it sees the word alignment pattern in a new word boundary.
The rx_syncstatus and rx_patterndetect signals, with the same latency as the datapath, are forwarded to the FPGA fabric to indicate the word aligner status.
After receiving the first word alignment pattern after rx_std_wa_patternalign is asserted, both rx_syncstatus and rx_patterndetect are driven high for one parallel clock cycle. Any word alignment pattern received thereafter in the same word boundary causes only rx_patterndetect to assert for one clock cycle. Any word alignment pattern received thereafter in a different word boundary causes the word aligner to re-align to the new word boundary only if rx_std_wa_patternalign is asserted. The word aligner asserts rx_syncstatus for one parallel clock cycle whenever it re-aligns to the new word boundary.