Arria® V Device Handbook: Volume 2: Transceivers

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

5.1.2.1. Rate Match FIFO Behaviors in Custom Single-Width Mode

The different operations available in custom single-width mode for the rate match FIFO are symbol insertion, symbol deletion, full condition, and empty condition.
Table 71.  Rate Match FIFO Behaviors in Custom Single-Width Mode (10-bit PMA–PCS Interface Width)
Operation Behavior
Symbol Insertion Inserts a maximum of four skip patterns in a cluster, only if there are no more than five skip patterns in the cluster after the symbol insertion.
Symbol Deletion Deletes a maximum of four skip patterns in a cluster, only if there is one skip pattern left in the cluster after the symbol deletion.
Full Condition Deletes the data byte that causes the FIFO to go full.
Empty Condition Inserts a /K30.7/ (9'h1FE) after the data byte that caused the FIFO to go empty.

In this example, /K28.5/ is the control pattern and neutral disparity /K28.0/ is the skip pattern. The first skip cluster has a /K28.5/ control pattern followed by two /K28.0/ skip patterns. The second skip cluster has a /K28.5/ control pattern followed by four /K28.0/ skip patterns. The rate match FIFO deletes only one /K28.0/ skip pattern from the first skip cluster to maintain at least one skip pattern in the cluster after deletion. Two /K28.0/ skip patterns are deleted from the second cluster for the three skip pattern deletion requirement.

Figure 138. Rate Match Deletion in Custom Single-Width ModeThe following figure shows an example of rate match FIFO deletion in the case where three skip patterns are required to be deleted.


In this example, /K28.5/ is the control pattern and neutral disparity /K28.0/ is the skip pattern. The first skip cluster has a /K28.5/ control pattern followed by three /K28.0/ skip patterns. The second skip cluster has a /K28.5/ control pattern followed by one /K28.0/ skip pattern. The rate match FIFO inserts only two /K28.0/ skip patterns into the first skip cluster to maintain a maximum of five skip patterns in the cluster after insertion. One /K28.0/ skip pattern is inserted into the second cluster for a total of three skip patterns to meet the insertion requirement.

Figure 139. Rate Match Insertion in Custom Single-Width ModeThe following figure shows an example of rate match FIFO insertion in the case where three skip patterns are required to be inserted.


Figure 140. Rate Match FIFO Full Condition in Custom Single-Width Mode The following figure shows the rate match FIFO full condition in custom single-width mode. The rate match FIFO becomes full after receiving data byte D4.


Figure 141. Rate Match FIFO Empty Condition in Custom Single-Width ModeThe following figure shows the rate match FIFO empty condition in custom single-width mode. The rate match FIFO becomes empty after reading out data byte D3.