User guide

76 www.xilinx.com Virtex-5 FPGA Integrated Endpoint Block
UG197 (v1.5) July 22, 2009
Chapter 4: Integrated Endpoint Block Operation
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Table 4-4 summarizes how different types of errors are reported and the actions taken by
the user.
Message Tags
The integrated Endpoint block supports the use of either 5-bit or 8-bit (extended) Message
Tags. The Extended Tag Field Supported bit is permanently enabled in the Device
Capabilities register and the choice of tag-length depends on the Extended Tag Field
Enable bit in the Device Control register. If 5-bit tags are used, the remaining three bits of
the tag field should be set to zero. Any nonzero bits within the remaining three bits of the
tag field can cause the integrated Endpoint block to report an unsupported request.
Phantom Function Support
The integrated Endpoint block supports the use of Phantom Functions. The Phantom
Functions Supported bits of the Device Capabilities register are set to 01, indicating single
bit support. Functions 0, 1, 2, and 3 can claim functions 4, 5, 6, and 7 as Phantom Functions,
respectively. If the Phantom Function Number Enable bit is set, the maximum possible
number of outstanding requests requiring completion can be increased beyond 256 by
using Function Numbers not assigned to implemented functions to logically extend the tag
identifier.
Table 4-4: Error Reporting with User Action
Error Detected Action by User
Errors Flagged by Transaction Layer
Completer Abort
Action when
Transmitter
(i.e., the Completer)
Assert
L0SETUSERSIGNALLEDTARGETABORT
port.
Action when
Receiver (i.e.,
receiver of the
completion)
Assert
L0SETUSERRECEIVEDTARGETABORT
port.
Malformed TLP
Action when
Receiver
Assert
L0SETDETECTEDFATALERROR port.
Poisoned TLP
Action when
Receiver
Assert
L0SETUSERMASTERDATAPARITY port
only if it is a completion TLP. If it is not an
advisory non-fatal error, assert
L0SETDETECTEDNONFATALERROR port,
otherwise do not assert it.
Completion with
Unsupported
Request
Action when
Receiver
Assert
L0SETUSERRECEIVEDMASTERABORT
port.