RTOS/AM4378: Inaccuracy of Timer Module

NAncy,

What is the input clock to DMtimer on the board ? Is this on the EVM or IDK or custom board.  I would recommend customer to refer to pm_a9.cfg to see how timer can be configured.  I suspect that the timer input is set to 20 MHz but the board is using 24 MHz so  it is generating incorrect timing based on this input clock.

The correct syntax of using timer and configuring input clock to timer 3 and 4 is as shown below

/***********************************************

*           Timer Module Configuraion         *

***********************************************/

/* Set to 1-ms Tick and Enable Wakeup for OVF interrupt */

var Timer = xdc.useModule('ti.sysbios.timers.dmtimer.Timer');

var timerParams = new Timer.Params();

timerParams.period = 1000 * 10;

timerParams.twer.ovf_wup_ena = 1;

timerParams.tiocpCfg.emufree = 1;

timerParams.tsicr.posted = 0;

/* Timer ID = 3 for GPTimer2 and input clock runs at 24 MHz */

Timer.intFreqs[3].hi = 0;

Timer.intFreqs[3].lo = 24000000;

Timer.create(3, '&mainTimerTick', timerParams);

/* Assign GPTimer4 to be used for Timestamp */

/* Timer ID = 4 for GPTimer4 and input clock runs at 24 MHz */

var DMTimer = xdc.useModule('ti.sysbios.timers.dmtimer.Timer');

var timerParams2 = new DMTimer.Params();

timerParams2.tsicr.posted = 0;

DMTimer.intFreqs[4].hi = 0;

DMTimer.intFreqs[4].lo = 24000000;

var DMTimestampProvider = xdc.useModule("ti.sysbios.timers.dmtimer.TimestampProvider");

DMTimestampProvider.timerId = 4;

DMTimestampProvider.useClockTimer = false;

var Timestamp = xdc.useModule("xdc.runtime.Timestamp");

Timestamp.SupportProxy = DMTimestampProvider;

/* Indicate GPT3 & GPT4 are used */

var TimerSupport = xdc.useModule('ti.sysbios.family.arm.a9.am437x.TimerSupport');

TimerSupport.availMask = 0x0018;

Hope this helps

Regards,

Rahul

PS: Refer to TI RTOS notes provided here:

http://processors.wiki.ti.com/index.php/Processor_SDK_RTOS:_TI_RTOS_Tips_And_Tricks#How_to_get_accurate_clock_ticks_from_the_clock_module.3F