TMS320F28379D: Initialize CPU-Timer settings

Hamed Pourgharibshahi

Part Number: TMS320F28379D

Hello TI,

I am wondering what is the initial timer interrupt in this TI example code:

// Initialize timer period to maximum:
//
CpuTimer0Regs.PRD.all = 0xFFFFFFFF;
//
// Initialize pre-scale counter to divide by 1 (SYSCLKOUT):
//
CpuTimer0Regs.TPR.all = 0;
CpuTimer0Regs.TPRH.all = 0;

Microcontroller is a TMS320F28379D chip with 200MHz. I think the timer should work with 5us interrupt based on these settings, but I am not sure.

Also, I know easy method is using "ConfigCpuTimer(&CpuTimer0, 200, ....);" , but it is not using this function in any part of the code for this timer. So, just the initialize settings exists.

Could you please help me with the mathematical cellulation of its time?

over 1 year ago

0 Omer Amir over 1 year ago

TI__Mastermind 30185 points

Hello Hamed,

The register stores the number of SYCLKs for the timer's period, so if the period is 100 this translates to 100 SYSCLK cycles. For a 200 MHz device, this is 100 * (1/200 MHz) or 500 ns. The configCPUTimer function I believe you're referring to uses the parameter in terms of microseconds and within the function itself translates this to number of SYSCLKs. There is nothing unique about this, you simply need to translate from the time domain to frequency domain (i.e. from cycles to seconds).