Unsupported Request - 3.0 English

AXI Bridge for PCI Express Gen3 Subsystem Product Guide (PG194)

Document ID
PG194
Release Date
2022-11-16
Version
3.0 English

A device for PCIe might not be capable of satisfying a specific read request. For example, if the read request targets an unsupported address for PCIe, the completer returns a completion TLP with a completion status of 0b001 - Unsupported Request. The completer that returns a completion TLP with a completion status of Reserved must be treated as an unsupported request status, according to the PCI Express Base Specification v3.0. When the slave bridge receives an unsupported request response, the Slave Unsupported Request (SUR) interrupt is asserted and the DECERR response is asserted with arbitrary data on the AXI4 memory mapped bus.