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Re: IRQ problem


The ETRAX 100LX / ETRAX 100MCM interrupt is not pulse triggered.
You have to keep the interrupt low until it is acknowledged.
If you just apply a short pulse you may miss it. 

Per Zander 

On Fri, 21 Feb 2003, Nagy Zsolt wrote:

> I have a problem with using the IRQ pin on Etrax 100MCM.
> I installed the following components on my Linux system:
> - crist-dist 1.22
> - e100lx_mcm R1_0_0
> - Linux kernel 2.4.19
> Enabled devices in the kernel configuration are ethernet,  async. serial 3,
> GPIO and my own driver in .
> In my driver I initialize IRQ with a code like this:
>  *R_IRQ_MASK0_CLR = 0x00000020;
>  *R_IRQ_MASK0_SET = 0x00000010;
> request_irq(10, irqfunction 0, devicename, 0);
> With my external hardware I normally keep IRQ high, but when generating
> interrupt an about 400 ns wide negative pulse is applied.
> The problem is that some of the interrupts are lost: the IRQ function is not
> executed although the pulse on the pin is OK.
> Thanks for any help.
> Zsolt Nagy