Zero Length Requests - 1.0 English

Versal ACAP DMA and Bridge Subsystem for PCI Express Product Guide (PG344)

Document ID

PG344

Release Date

2022-05-20

Version

1.0 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.