Arria® V Device Handbook: Volume 2: Transceivers

ID 683573
Date 5/29/2020
Public
Document Table of Contents

1.2.2.1.3. Word Aligner in Automatic Synchronization State Machine Mode

In automatic synchronization state machine mode, a programmable state machine determines the moment that the word aligner has either achieved synchronization or lost synchronization.

You can configure the state machine to provide hysteresis control during link synchronization and throughout normal link operation. Depending on your protocol configurations, the state machine parameters are automatically configured so they are compliant with the synchronization state machine in the respective protocol specification.

Table 26.  State Machine Parameters for the Word Aligner in Automatic Synchronization State Machine Mode
Parameter Values
Number of valid synchronization code groups or ordered sets received to achieve synchronization 1–256
Number of erroneous code groups received to lose synchronization 1–64
Number of continuous good code groups received to reduce the error count by one 1–256
Table 27.  Word Aligner Operation in Automatic Synchronization State Machine Mode
PCS Mode PMA–PCS Interface Width Word Alignment Operation
Single Width 10 bits
  1. After the rx_digitalreset signal deasserts, the word aligner starts looking for the predefined word alignment pattern, or its complement, in the received data stream and automatically aligns to the new word boundary.
  2. Synchronization is achieved only after the word aligner receives the programmed number of valid synchronization code groups in the same word boundary and is indicated by the value 1 in rx_syncstatus register. The rx_syncstatus register contains a value 0 if the word aligner has lost synchronization.
  3. Loss of synchronization occurs when the word aligner receives the programmed number of erroneous code groups without receiving the intermediate good code groups and is indicated by the value 0 in the rx_syncstatus register.
  4. The word aligner may achieve synchronization again after receiving a new programmed number of valid synchronization code groups in the same word boundary.