Intel® Arria® 10 Transceiver PHY User Guide

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ID 683617
Date 3/28/2022
Public
Document Table of Contents

2.8.3. Word Aligner in Manual Mode for CPRI

When configuring the word aligner in CPRI (Manual), the word aligner parses the incoming data stream for a specific alignment character. After rx_digitalreset deasserts, asserting the rx_std_wa_patternalign triggers the word aligner to look for the predefined word alignment pattern or its complement in the received data stream. It is important to note that the behavior of the word aligner in Manual mode operates in different ways depending on the PCS-PMA interface width.
Word Aligner Signal Status Behaviors in Manual Mode
PCS-PMA Interface Width rx_std_wa_patternalign Behavior rx_syncstatus Behavior rx_patterndetect Behavior
10 Level sensitive One parallel clock cycle (When three control patterns are detected) One parallel clock cycle
20 Edge sensitive Remains asserted until next rising edge of rx_std_wa_patternalign One parallel clock cycle

PCS-PMA Width = 10

When the PCS-PMA interface width is 10, 3 consecutive word alignment patterns found after the initial word alignment in a different word boundary causes the word aligner to resynchronize to this new word boundary if the rx_std_wa_patternalign remains asserted; rx_std_wa_patternalign is level sensitive. If you deassert rx_std_wa_patternalign, the word aligner maintains the current word boundary even when it finds the alignment pattern in a new word boundary. When the word aligner is synchronized to the new word boundary, rx_patterndetect and rx_syncstatus are asserted for one parallel clock cycle.

PCS-PMA Width =20

When the PMA-PCS width is 20, any alignment pattern found after the initial alignment in a different word boundary causes the word aligner to resynchronize to this new word boundary on the rising edge of rx_std_wa_patternalign; rx_std_wa_patternalign is edge sensitive. The word aligner maintains the current word boundary until the next rising edge of rx_std_wa_patternalign. When the word aligner is synchronized to the new word boundary, rx_patterndetect asserts for one parallel clock cycle and rx_syncstatus remains asserted until the next rising edge of rx_std_wa_patternalign.

Figure 118. Word Aligner in Manual Alignment Mode Waveform

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