Altera Arria 10 Avalon-ST - Manual (Page 262)

Possible Causes Symptoms and Root Causes Workarounds and Solutions
Malformed TLP is
transmitted
Refer to the error log file to find
the last good packet transmitted
on the link. Correlate this packet
with TLP sent on Avalon-ST
interface. Determine if the last
TLP sent has any of the
following errors:
• The actual payload sent does
not match the length field.
• The format and type fields
are incorrectly specified.
• TD field is asserted,
indicating the presence of a
TLP digest (ECRC), but the
ECRC dword is not present
at the end of TLP.
• The payload crosses a 4KByte
boundary.
Revise the Application Layer logic to correct the
error condition.
Insufficient Posted
credits released by
Root Port
If a Memory Write TLP is
transmitted with a payload
greater than the maximum
payload size, the Root Port may
release an incorrect posted data
credit to the Endpoint in
simulation. As a result, the
Endpoint does not have enough
credits to send additional
Memory Write Requests.
Make sure Application Layer sends Memory
Write Requests with a payload less than or equal
the value specified by the maximum payload
size.
Missing completion
packets or dropped
packets
The RX Completion TLP might
cause the RX FIFO to overflow.
Make sure that the total
outstanding read data of all
pending Memory Read Requests
is smaller than the allocated
completion credits in RX buffer.
You must ensure that the data for all
outstanding read requests does not exceed the
completion credits in the RX buffer.
Related Information
• PIPE Interface Signals on page 6-57
• Avalon Interface Specifications
• PCI Express Base Specification 3.0
• Design Debugging Using the SignalTap II Embedded Logic Analyzer
18-4 Debugging Link Failure in L0 Due To Deassertion of tx_st_ready
UG-01145_avst
2015.05.04
Altera Corporation Debugging
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