1 Reply Latest reply on Apr 9, 2010 6:04 PM by ananda_26

    Seeing a second interrupt

              I am using the CY7C64013 USB controller and have a question.   
      I have set Endpoint2 to be Interrupt OUT and Endpoint4 to be Interrupt IN. I am using visual basic to generate a writefile API call to trigger the Endpoint2 Interrupt. This works fine. However, while in the Endpoint2 interrupt service routine, I need to send data back to the host using Endpoint4.   
      Question: While in the Endpoint2 interrupt service routine, is the CY7C64013 capable of seeing another interrupt on Endpoint4? I am not able to do this. I believe the CY7C64013 interrupt system is disabled as soon as an interrupt is generated, although I do not know if this is true.   
      I have re-enabled interrupts a soon as I enter the Endpoint2 service routine, but my code is not able to see the Endpoint4 interrupt.   
      Is there any test code that would show me how to do this?   
      George Frueh   
        • 1. Re: Seeing a second interrupt
                  When dealing with USB protocol the abstraction to be in mind is in packets... when ep2 isr is triggered it means the host is sending in data... there is no way host can send a request in the middle of the packet to ep4 asking for a interrupt packet... if an in transfer is triggered by host right after the out transfer the ep4 isr should be triggered...