AM2432: Reducing timer callback time

Eli Mordel

Part Number: AM2432
Other Parts Discussed in Thread: SYSCONFIG

Tool/software:

Hi,

I'm working with the AM2432 CPU and have configured a hardware timer with a 62 µs period using SysConfig.

I've measured the time from the moment the timer expires to when the registered callback function is invoked, and it takes at least 1 µs.

Is there a way to reduce this latency further — for example, by configuring the VIM to perform a direct jump to the ISR (bypassing SDK-level wrappers or indirection)?

Thanks,
Eli

5 months ago

0 Vaibhav Kumar 5 months ago

TI__Mastermind 45976 points

Hi Eli,

Please let me know if the following is a correct understanding.

Timer of 62 Microseconds set up.

So expected functionality from your end is:

After 62 microsecond, callback function executes

But you are seeing:

After 62 microseconds, + 1 microsecond + callback function executes.

Regards,

Vaibhav

0 Eli Mordel 5 months ago in reply to Vaibhav Kumar

Expert 1355 points

Hi Vaibhav,

Yes , thats exactely what I measure.

Is it possible to register directely in VIM to further reduce this 1usec ?

Thanks,

Regards,

Eli

0 Vaibhav Kumar 5 months ago in reply to Eli Mordel

TI__Mastermind 45976 points

Hi Eli,

Eli Mordel said:
Is it possible to register directely in VIM to further reduce this 1usec ?

Allow sometime for another expert to comment on the same.

Regards,

Vaibhav

0 Eli Mordel 5 months ago in reply to Vaibhav Kumar

Expert 1355 points

Thanks Vaibhav.

0 Tushar Thakur 5 months ago in reply to Eli Mordel

TI__Mastermind 49888 points

Hi Eli,

Eli Mordel said:
I've measured the time from the moment the timer expires to when the registered callback function is invoked, and it takes at least 1 µs.

When an interrupt is generated for the core, the registered callback function is executed from the master HwiP_irq_handler_c() isr handler API.

Before calling this API or the callback function, there are some assembly logic which needs to be executed which will help in save and restore the context before entry and exit of the ISR callback.

This assembly instructions which branches the ISR will take some time for it's execution before entry of callback and after exiting the callback. So the delay which you are seeing is expected.

Regards,

Tushar

0 Eli Mordel 5 months ago in reply to Tushar Thakur

Expert 1355 points

Thanks Tushar,

Regards,

Eli

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AM2432: Reducing timer callback time