Zero Length Requests - 4.0 English

QDMA Subsystem for PCI Express Product Guide (PG302)

Document ID
PG302
Release Date
2022-05-20
Version
4.0 English

When the master bridge receives a read request with the Length = 0x1, FirstBE = 0x00, and LastBE = 0x00, it responds by sending a completion with Status = Successful Completion.

When the master bridge receives a write request with the Length = 0x1, FirstBE = 0x00, and LastBE = 0x00 there is no effect.

Table 1. Master Bridge Response to Abnormal Conditions
Transfer Type Abnormal Condition Bridge Response
Read DECERR response

MDE interrupt strobe asserted.

Completion returned with Unsupported Request status.

Write DECERR response MDE interrupt strobe asserted.
Read SLVERR response

MSE interrupt strobe asserted.

Completion returned with Completer Abort status.

Write SLVERR response MSE interrupt strobe asserted.
Write Poison bit set in request

MEP interrupt strobe asserted.

Data is discarded.

Read DECERR response

MDE interrupt strobe asserted.

Completion returned with Unsupported Request status.

Write DECERR response MDE interrupt strobe asserted.