TMS320F280049C: SYS/BIOS Timer0 issue.

Pradeep choudhary

Part Number: TMS320F280049C

Hi,

I am using timer 0 on TMS320F280049C and using SYS_CLOCK at 100 MHz for this timer and I am trying to set a different period for the timer(After every period, I am toggling GPIO and monitoring that GPIO on scope). But when I set the period of timer below 50 us. I start getting a non-periodic signal on the scope. My project is using SYS/BIOS. SYS/BIOS is using timer 2 and the tick period is set to 1 ms. Please let me know why such behavior is occurring.

I am attaching snaps of the signal(period of 10 us).

Hoping for a quick help.

Thanks and Regards,

PradeepSignal.pdf

over 4 years ago

0 Whitney Dewey over 4 years ago

TI__Guru 53765 points

Are you using the SYS/BIOS Timer module or are you actually configuring the CPU Timer registers and creating a Hwi for the interrupt? Do you mind sharing the interrupt function? Are there many other Hwis configured?

Whitney

0 Pradeep choudhary over 4 years ago in reply to Whitney Dewey

Intellectual 310 points

I am configuring CPU timer registers and creating HWI for the interrupt.

My HWI creation code and Interrupt function is as follows-

/**** Hwi Creation ****/
hwi0=Hwi_create(38,(Hwi_FuncPtr)myISR,NULL,NULL);
if (hwi0 == NULL)
{
    System_abort("Hwi create failed");
}

void myISR(UArg arg)
{   
    GPIO_togglePin(DEVICE_GPIO_PIN_LED1);
}

Thanks and Regards,

Pradeep

0 Whitney Dewey over 4 years ago in reply to Pradeep choudhary

TI__Guru 53765 points

Judging from the SYS/BIOS benchmarks, the interrupt latency may account for some of that at 10us. You may want to try making that interrupt a "zero latency" interrupt instead of a regular Hwi to see if removing the dispatcher overhead from the equation fixes the issue. There are some slides explaining the concept here:

https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/171/4555.C28_5F00_zero_5F00_latency.pdf

Whitney

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TMS320F280049C: SYS/BIOS Timer0 issue.