EVM365: Hardware Timer Utilization

Ken Koller said:

I have a need for one of the timers. Is there documentation regarding which hardware peripherals are being used by Linux? Specifically, which timers are free?

Sure, check out section 1.6 of SPRS566, though the DM365 description is somewhat disconcerting as it does not mention which is beign used as the Linux system tick, though it is quite likely that DM365 uses the same timers as the other platforms, if all else fails you could try a particular timer and see what happens or look into the kernel source.

I keep forgetting to look at the PDFs that ship with the software. Thanks for not RTFMing me :)

Hm. The 365 section is a bit vague but I'll figure something out.

Like the new avatar :)

Hi Ken,

I happend to have the same issue. Did you ever figure out which timer on DM365 is free to use?

Thanks,

Xiangdong

Hi Xiangdong,

It turned out that I didn't need the timer after all (I managed to create the timing I needed by other means). However the interrupt IRQs map to the interrupt number of the interrupt controller's vector table. So perhaps if you look at /proc/interrupts (I think this is correct) and compare that to the table published in the DM365 user guide you can determine which are being used.

Good luck.

Ken

Ken,

Thanks for the reply. I digged into the kernel source and also confirmed by looking at timer register settings at run-time using devmem. It turned out that Linux only uses timer 0 and 1(configured as 4 separate 32-bit timers, same for all Davinci familily devices). Timer 3 & 4 are not used.

Regards,

Xiangdong

Hi Xiangdong,

I am having quite a battle to get timer4 going.  When I started off wanting to use a counter I just started with timer0 and that broke my system so I could confirm that timer0 and timer1 is used by kernel and from datasheets that timer2 is used for wdt.  On my evmdm365 I then used timer3 and it worked like I wanted for a counter.  Then I needed a timer to clock my voice coded to generate a warning tone over the speaker connected to dm365.  I tried timer 4 but had no luck.  I then changed timer3 functionality and used it as a timer for pushing data into the voice codec and at least the interrupt was working although my tone is not working perfectly yet.  I tried to use timer4 as a counter where timer3 was used but also no luck.  At this stage I tried everything and timer4 is now exactly set up as timer3 was but I can not get it working.  Can TI confirm that timer4 is working and if there are anything special to be done to do so?  I do not use CCS and use dvsdk_2_18 with PSP examples.

Thanks, Jinh T.

hi, Jinh .

it's happy to see your post. i have the same problem with timer4 but.. i cannot even get timer3 works.

here is my post : http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/100/t/134735.aspx

please.. if you dont get any time to go though my post.. can you just put your code snippets here ..

it will be appreciated ..

regards Mike.

hope to see you post soon.