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Altera_Forum's avatar
Altera_Forum
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21 years ago

Cyclone SL811HS interrupts

I think there's a problem with the Cyclone Development Board.

I am using the NIOS-II Kitchen sink design, and I have coded a small USB driver for the board. I am now capable of performing a full enumeration sequence on Windows XP.

However - I am unable to get interrupts from the SL811HS controller into the NIOS-II core. So the way I've implemented the "driver" is by having a loop continuously polling the SL811HS's interrupt status register. The sample code which was presented in this forum, uses the same technique.

On the NIOS-1 examples, some sort of interrupt is used. I beleive it may run on a timer-interrupt instead of the "real" interrupt from the SL811HS - Is this correct?

If there is an issue with the USB controller and Interrupts, please let me know.

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    21 years ago

    The interface component we created to connect the SL811HS to the Avalon bus has an extra facility for enabling/diabling interrupts. The bit to allow interrupts to pass through lives in the 3rd register of our interface component (usb_base_address+8) at bit 2. Writing a 0x4 to this register will enable interrupts from the SL811HS to reach the Nios processor.

    I am emailing you the most recent version of our document describing our USB reference project (a similar document should have come on the CD with your board). It contains a description of our SL811HS-to-Avalon interface.

    Dennis Scott

    Microtronix Datacom Ltd.
  • Altera_Forum's avatar
    Altera_Forum
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    21 years ago

    Wow.. again.. brilliant support - thanks guys.

    Yes - it did work, I am now getting interrupts - I don't know if I missed something in the docs.

    To anyone following this discussion here's how I enabled interrupts from the SL811HS to the NIOS-II core..

    // you need this:

    //----------------------------------------------------------------------------------

    volatile unsigned int *pAddrSel = (unsigned int*) (USB_BASE);

    // write a single byte to the controller at addr

    void Write ( unsigned int addr, unsigned int value )

    {

    pAddrSel[0] = addr;

    pAddrSel[1] = value;

    }

    .

    .

    then somewhere in your code...

    .

    .

    // enable the interrupts to come through

    IOWR_ALTERA_AVALON_PIO_DATA(USB_BASE + 8, 0x04);

    // register an interrupt handler for the USB interrupts

    alt_irq_register (USB_IRQ, NULL, handle_USB_interrupts);

    // enable all interrupts from the controller

    Write ( REG_INTERRUPT_ENABLE, 0x7f );

    that's it...