Why are interrupts not working in my PCI Express End Point

Description

When using the Altera® IP Compiler for PCI Express®, interrupts will not work for all configurations of the IP, except for completer only single dword variants, if the CRA port is not connected.

The interrupt registers and control logic are only implemented if the CRA port is used, typically the CRA port will be connected to a BAR so that the Host can access this interface.