Device Family: Intel® Arria® 10 GT, Intel® Arria® 10 GX, Intel® Arria® 10 SX, Arria® V GT, Arria® V GX, Arria® V GZ, Arria® V ST, Stratix® V GS, Stratix® V GT, Stratix® V GX

Type: Answers

Area: Intellectual Property


IP Product: PCI Express Gen 3,2 or 1 x8,4,2,1 Hardened IP

Why does my V-Series Avalon-MM DMA for PCIe hang with Txs_waitrequest low?

Description

You will see this behavior if you accidentally issue a DMA request for zero bytes.  The request is correctly sent to the Host, but will be ignored, causing the Altera® Hard IP for PCI® Express to hang waiting on a response from the Host.

Workaround/Fix

To correct this, ensure that all DMA requests are for > 0 bytes.