I'm having trouble in generating an MSI in my Endpoint FPGA. I am using Cyclone 10 GX with "Hard IP for PCI Express"(Avalon-MM) and DMA support. The MSI is already working when a DMA transaction completes, but I want to send another one defined by the application logic. I tried to use the Avalon-MM to PCI Express Mailbox Registers (0x3A00) and the Avalon-MM to PCI Express Interrupt Enable Register (0x0050) from CRA, but I don't receive any MSI at the RootPort site. It also seems that the IER cannot be accessed in WRITE mode.