Cyclone SL811HS interrupts

Altera_Forum · ‎09-02-2004

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.

Altera_Forum · ‎09-02-2004

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 · ‎09-02-2004

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...