Error
Type
Description
In all cases the TLP is deleted in the Hard IP block and
not presented to the Application Layer. If the TLP is a
non-posted request, the Hard IP block generates a
completion with Unsupported Request status.
Completion timeout
Uncorrectable
(non-fatal)
This error occurs when a request originating from the
Application Layer does not generate a corresponding
completion TLP within the established time. It is the
responsibility of the Application Layer logic to provide
the completion timeout mechanism. The completion
timeout should be reported from the Transaction Layer
using the
cpl_err[0]
signal.
Completer abort
(1)
Uncorrectable
(non-fatal)
The Application Layer reports this error using the
cpl_
err[2]
signal when it aborts receipt of a TLP.
Unexpected completion
Uncorrectable
(non-fatal)
This error is caused by an unexpected completion
transaction. The Hard IP block handles the following
conditions:
• The Requester ID in the completion packet does not
match the Configured ID of the Endpoint.
• The completion packet has an invalid tag number.
(Typically, the tag used in the completion packet
exceeds the number of tags specified.)
• The completion packet has a tag that does not match
an outstanding request.
• The completion packet for a request that was to I/O
or Configuration Space has a length greater than 1
dword.
• The completion status is Configuration Retry Status
(CRS) in response to a request that was not to
Configuration Space.
In all of the above cases, the TLP is not presented to the
Application Layer; the Hard IP block deletes it.
The Application Layer can detect and report other
unexpected completion conditions using the
cpl_
err[2]
signal. For example, the Application Layer can
report cases where the total length of the received
successful completions do not match the original read
request length.
9-4
Transaction Layer Errors
UG-01145_avmm_dma
2015.11.02
Altera Corporation
Error Handling
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