Clarification regarding user interrupts (irq_req)

0

Hi,

the Shell specification says:

This interface uses single clock pulses for the req/ack. The CL asserts (active high) cl_sh_apppf_irq_req[x] for a single clock to assert the interrupt request to the SH. The SH will respond with a single clock pulse on sh_cl_apppf_irq_ack[x] to acknowledge the interrupt.

As I understand it, the Shell uses the Xilinx PCIe DMA core (XDMA) for DMA and user interrupts. Xilinx PG195 says about the user interrupts:

After a usr_irq_req bit is asserted, it must remain asserted until the corresponding usr_irq_ack bit is asserted. The usr_irq_ack bit assertion indicates the requested interrupt has been sent on PCIe. For MSI-X, once this ack has been observed, the usr_irq_req bit can be deasserted.

Does the shell have additional logic to handle this requirement? I.e. does my CL need to send a single clock pulse as stated in the shell specification or must the CL assert the request line until it got ack'ed?

miob
asked 5 years ago332 views
1 Answer
0

Hello Miob,
Thank you for the query. I would suggest you to follow the SH/CL spec. So please send a pulse instead of a level based trigger.

Regards
Bala

answered 5 years ago

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