SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
Legacy PCI interrupts are supported over PCIe by dedicated message codes (posted-write in Msg space) that flag the assertion or deassertion of one of four "virtual" interrupt lines (or pins): INTA, INTB, INTC, INTD. They can only be sent by EPs, and routed to/received by the RC.
PCIe controller supports single-function mode and can send only INTA when configured as EP.
Use of legacy PCI interrupt is exclusive with use of MSI (defined in Section 24.9.4.6.2.1.2). MSI should be the preferred method whenever possible.