Intel Arria 10 User Manual page 234

The PIPE core provides a 1-bit PHY status signal
receiver status signal
detected, as per the PIPE 2.0 specifications.
2.7.2.1.7. Gen1 and Gen2 Clock Compensation
In compliance with the PIPE specification, Arria 10 receiver channels have a rate
match FIFO to compensate for small clock frequency differences up to ±300 ppm
between the upstream transmitter and the local receiver clocks.
Consider the following guidelines for PIPE clock compensation:
• Insert or delete one SKP symbol in an SKP ordered set.
• Minimum limit is imposed on the number of SKP symbols in SKP ordered set after
deletion. An ordered set may have an empty COM case after deletion.
• Maximum limit is imposed on the number of the SKP symbols in the SKP ordered
set after insertion. An ordered set may have more than five symbols after
insertion.
• For INSERT/DELETE cases: The flag status appears on the COM symbol of the SKP
ordered set where insertion or deletion occurs.
• For FULL/EMPTY cases: The flag status appears where the character is inserted or
deleted.
Note: When the PIPE interface is on, it translates the value of the flag to the
• The PIPE mode also has a "0 ppm" configuration option that you can use in
synchronous systems. The Rate Match FIFO Block is not expected to do any clock
compensation in this configuration, but latency is minimized.
Figure 92. Rate Match Deletion
This figure shows an example of rate match deletion in the case where two /K28.0/ SKP symbols must be
deleted. Only one /K28.0/ SKP symbol is deleted per SKP ordered set received.
rmfifo_input_data
rx_parallel_data
pipe_rx_status[2:0]
® ®
Intel Arria 10 Transceiver PHY User Guide
234
pipe_rx_status[2:0]
appropriate
pipe_rx_status
First SKP Ordered Set
K28.5 K28.0 Dx.y
K28.5 Dx.y K28.5
3'b010 xxx 3'b010
2. Implementing Protocols in Arria 10 Transceivers
pipe_phy_status
to indicate whether a receiver is
signal.
SKP Symbol
Deleted
Second SKP Ordered Set
K28.5 K28.0 K28.0
Dx.y
K28.0 K28.0
xxx
xxx xxx
UG-01143 | 2018.06.15
and a 3-bit
Dx.y
K28.0