ARM920 Timer Counter Configuration

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
sjohnson Contact options for registered users 's Avatar (by Gravatar) posted on
December 18, 2006, 6:01 pm
rate this thread
Reply to this post Reply Tag this thread to save it in your account Save Printer-friendly version of this post Print
Hi,

Does anyone have any example code demonstrating how to configure a
timer/counter interrupt for the AT91 processor running Linux? I'm new
to running embedded Linux, and I can't seem to find any information out
on the net. All that I am really trying to do is generate a periodic
interrupt using one of  the built in timer/counter channels.

Any information would be greatly appreciated.

Thanks,
Steve

mailto: snipped-for-privacy@powereng.com


Other Related Threads
Rick Bronson Contact options for registered users 's Avatar (by Gravatar) posted on
December 18, 2006, 10:58 pm
Permalink
Reply to this post Reply Tag this thread to save it in your account Save Printer-friendly version of this post Print
Re: ARM920 Timer Counter Configuration
Try this http://maxim.org.za/at91_26.html
--
                                                                   _
                                                                  | |
We've slightly trimmed the long signature. Click to see the full one.
Other Related Threads
Michael Schnell Contact options for registered users 's Avatar (by Gravatar) posted on
December 19, 2006, 11:33 am
Permalink
Reply to this post Reply Tag this thread to save it in your account Save Printer-friendly version of this post Print
Re: ARM920 Timer Counter Configuration
You want to create a device driver kernel module.

So first you need to know how to create a device driver: "Linux device
drivers 3rd Edition" by Rubini and Friends.


Then you proceed according to the information the chips data sheet
provides.

-Michael

sjohnson Contact options for registered users 's Avatar (by Gravatar) posted on
December 19, 2006, 3:09 pm
Permalink
Reply to this post Reply Tag this thread to save it in your account Save Printer-friendly version of this post Print
Re: ARM920 Timer Counter Configuration

Quoted text here. Click to load it


Thanks, Michael. I am able to build a device driver without a problem.
I guess my real question is how to actually configure the timer counter
in Linux for the AT9200RM processor. I have found an application note
on the Atmel site that describes the process without using an OS. My
problem is that I'm not sure what to do in Linux. Here's what I am
trying, but I think its totally wrong:

volatile AT91PS_TCB p_tcb = (AT91PS_TCB)AT91C_VA_BASE_TCB0;
volatile AT91PS_TC  p_tc  (AT91PS_TC)&p_tcb->TCB_TC0;
...

status = request_irq(AT91C_ID_TC0, timer_isr, SA_INTERRUPT,
"timer_isr", NULL);
if ( !status ) {
    p_tc->TC_CCR = AT91_TC_CLKDIS;
    p_tc->TC_IDR = AT91C_TC_CPCS;
    dummy = p_tc->TC_SR;
    p_tc->TC_CMR = AT91C_TC_TIMER_DIV2_CLOCK | AT91C_TC_CPCTRG;
    p_tc->TC_CCR = AT91C_CLKEN;
    p_tc->TC_IER = AT91C_TC_CPCS;
    p_tc->TC_RC = 0x00ff;
    p_tc->TC_CCR = AT91C_TC_SWTRG;
}
....

}


Site Timeline