Hi Simon,

You can also use a 32-bit timer lets say running at 50MHz and use pre-scale
of 50 so that you get tick at every 1us.


Thanks and Regards,
Rakendra

On Fri, Jul 10, 2015 at 2:40 PM, Simon Vincent <[email protected]>
wrote:

> Ok maybe I will leave timers alone for a couple of weeks and redo them
> once the new timers hit master.
>
> I hope to make all the Zynq port code available in a few weeks.
>
> Simon
>
>
> On 10/07/15 09:53, Kaspar Schleiser wrote:
>
>> Hey,
>>
>> On 07/10/15 10:32, Simon Vincent wrote:
>>
>>> Currently the issue I get with multiple timers is that calls to
>>> hwtimer_arch_now do not specify a timer. So you call hwtimer_arch_now
>>> and get a value. If you then use this to set a delay there are problems
>>> as when you request this delay it could use a different hwtimer. This
>>> currently occurs in vtimers.
>>>
>> hm, did you implement hwtimer for your architecture? The implementation
>> should use only timers that run at the same speed.
>>
>>  In order to harmonize platforms, if possible make one timer, preferably
>>>> timer 0, run at 1MHz.
>>>>
>>> What if my platform does not have a 1MHz timer? Is there going to be
>>> problems?
>>>
>> No. Right now, wtimer is just missing support for that.
>>
>>  Check PR #2926 to see where we're headed.
>>>>
>>> Ok I will have a look. When do you think it will ready?
>>>
>> I'd say, until it is the default timer in master, a couple of weeks.
>> I hope to have it ready as experimental drop-in-replacement before the
>> IETF (next week).
>>
>>  May I ask which platform you are porting to?
>>>>
>>> Currently I am porting to the Zynq 7000 which contains a Arm Cortex A9.
>>>
>> Very interesting! If possible, please let as see the code. ;)
>>
>>  Currently I have implemented as the periph/timer the three 16-bit timers
>>> running at 0.78MHz (closest I can get to 1MHz). This works well using
>>> hwtimers for short delays but vtimer does not work at all as the timers
>>> overflow too quickly.
>>>
>> You could try to fake 32bit timers (in software or by combining two
>> timers).
>>
>> If you only need the timer for your application, take a look at #2926.
>> wtimer has support for 16bit timers and handles overflows a lot better.
>>
>> Kaspar
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