Completions with Error Status (UR and CA) - 1.0 English

Versal Adaptive SoC Integrated Block for PCI Express LogiCORE IP Product Guide (PG343)

Document ID
PG343
Release Date
2024-05-30
Version
1.0 English

When responding to a request received on the completer request interface with an Unsupported Request (UR) or Completion Abort (CA) status, the user logic must send a 3-Dword completion descriptor in the format of the Completer Completion Descriptor Format figure in Completer Completion Descriptor Format, followed by five additional Dwords containing information on the request that generated the Completion. These five Dwords are necessary for the core to log information about the request in its AER header log registers.

The following figure shows the sequence of information transferred when sending a Completion with UR or SC status. The information is formatted as an AXI4-Stream packet with a total of 8 Dwords, which are organized as follows:

  • The first three Dwords contain the completion descriptor in the format of the Completer Completion Descriptor Format figure in Completer Completion Descriptor Format.
  • The fourth Dword contains the state of the following signals in m_axis_cq_tuser, copied from the request:
    • The First Byte Enable bits first_be[3:0] in m_axis_cq_tuser.
    • The Last Byte Enable bits last_be[3:0] in m_axis_cq_tuser.
  • The four Dwords of the request descriptor received from the core with the request.
Figure 1. Composition of the AXI4-Stream Packet for UR and CA Completions