Re: About PCI Express generate a "Interrupt request" to Nios(Use DE2i-150)

Altera_Forum · ‎07-13-2016

Now I want to extend the project "pcie_fundamental" in system CD, but I meet some problems in software and Qsys part.

My target is generate a "interrupt" from PCIE at PC host, and deal with it in "nios ii for eclipse".

As shown in appendix "Qsys.JPG", I connect "PCIE Hard IP Compiler" and "Nios Processor" in IRQ(Interrupt request).

(If it has a connect error, please tell me.)

Qsys.JPG: https://drive.google.com/open?id=0b7gv38ouppiayupymfhrudbkavk

These are my questions:

1. How to generate a "interrupt request" from PCI Express to Nios?

2. Could I use below method to generate "Interrupt request"?

img1:https://drive.google.com/open?id=0b7gv38ouppiaoho3vzjkznbemle

img2:https://drive.google.com/open?id=0b7gv38ouppiaqvl6z2plmeledm8

img3:https://drive.google.com/open?id=0b7gv38ouppiarnbjewpkvgvaafe

Article mentioned that "Enables assertion of Avalon-MM interrupt CraIrq_o signal when the specified mailbox is written by the root complex".

How to enable "interrupt to Avalon MM", like this below(This C++ code in software part, and i try to enable P2A_MB_IRQ[0])?

(If it has a any error, please tell me.)

img:https://drive.google.com/open?id=0b7gv38ouppiar3rdmwlhlurlmmm

3. If above mentioned part is right, how to handle "Interrupt" when Nios II receive a IRQ(interrupt request queue)?

Could I register a ISR(Interrupt Service Routine) like below?

alt_irq_register(PCIE_HARD_IP_IRQ, 0, ISR);

Now I focus on What is PCI Express generate a interrupt request and Nios how to receive interrupt and how to handle it?

Appendixes "Qsys part" and "software part" can help you realize my question.

Qsys Part: https://drive.google.com/open?id=0b7gv38ouppiabkztvgztsdj3dza

Software Part: https://drive.google.com/open?id=0b7gv38ouppiaam12mg5ibkjhngs

(software part is use in PC host, not in use in "Nios II for Eclipse")

IP Compiler for PCI Express User Guide:

https://www.altera.com/content/dam/altera/www/global/en_us/pdfs/literature/ug/ug_pci_express.pdf (https://www.altera.com/content/dam/altera-www/global/en_us/pdfs/literature/ug/ug_pci_express.pdf)

DE2i_150 FPGA System User Manual:

http://www.terasic.com.tw/cgi-bin/page/archive_download.pl?language=english&no=529&fid=c10b5ed89f1ec9f4b578f1407255b340

Sincerely yours, Williams

Altera_Forum · ‎07-13-2016

I don't think PCI express was designed for the PC to send an interrupt to the card. You might be able to write some HDL code to generate an interrupt to your processor when a specific address on the card is written to by the PC.

Altera_Forum · ‎07-20-2016

Write HDL code is a method, but I want to know how to use "Generate a 'Avalon-MM Interrupt' " about PCI express Hard IP compiler.

Could you give me some example?