NIOS 2 SPI as SLAVE

You are correct with your assumption.

The FPGA will be part of a device that performs specific tasks and will be remotely controlled via SPI form a different device.

So we implemented a SPI interface with the new Qsys and configured it to behave as a SPI Slave device.

I have taken a look in the guide before but I am afraid I need more guidance.

My specific Problem is this:

The FPGA will receive a Command String from another device telling it what to do.

I need to understand how I can activate the SPI interrupt in C, so that everytime a transmission is started the interrupt handler can do what I need it to do. I believe I need to register the interrupt or something and define the handler.

SO far I tried this:

Initialising:

void init_spi{
/* Enable SPI read-ready interrupt */
  alt_irq_register(SPI_0_IRQ, (void*) &spi_context, handler_spi_isr);
}

handler:

static void slave_spi_isr(void* context, alt_u32 id)
{
  printf("Works, yay!\n");
}

I put that in the Hello_World example and it compiles okay.

But an spi command send to the fpga does not trigger the

handler. What's weird though, when I did the same inside the

NIOS 2 Debugging enviroment, there was an error message

telling me "target faild to interrupt".

I am sorry, if my questions or my confusion seems stupid,

but I am more used to 8-bit architectures, where I can look

up the internal register structure of a given processors

hardware and where I know every Register by heart.