CC2652R7: SysCtrlSystemReset not able to reset the chip and chips get stuck/bricked

Part Number: CC2652R7

Tool/software:

Hi All,

Trying to troubleshoot an odd and a very intermittent case where chips/tags just stop running - firmware just does not appear to run.

We do have watchdog implemented/added and I know it works, meaning if we don't extend the watchdog value in our code, it will reset. However, still at times we see tags that are just bricked, nothing appears to run. I am fairly certain no code is running when this happens. When we physically reset the tags by pulling the reset pin low, firmware starts right way and tag will work again.

Based on extensive debugging, we are seeing a case with SDK 7.10.01.24 and CC2652R7 chips, where when trying to reset the chip using SysCtrlSystemReset, the tags get bricked. We ran a test where we called SysCtrlSystemReset every 12 hrs, it ran for 4-5 days and then on the 10th attempt to reset (10th SysCtrlSystemReset call), tag got bricked.

Is there anything to check or measure to identify what is the state of the chip when it is in this mode? What can we do to prevent this from happening? Did anyone else experience similar behavior? Is there a better/different/recommended way to reset the chip from firmware other than SysCtrlSystemReset?

PS: In the meantime, we are running another test where before calling SysCtrlSystemReset, we added code to power down external sensors and reset cc2652R7 GPIOs such that any sensors, LEDs, buzzers, other modules the cc2652R7 is controlling, are ALL turned OFF when SysCtrlSystemReset is called. Also, cc2652R7 is receiving UART data from another MCU, we added code to stop UART data and power off the other MCU before calling SysCtrlSystemReset. I am suspecting, maybe it is power related issue of some sort and the code we added will help prevent this.

Here is the code for SysCtrlSystemReset from sys_ctrl.h:

It does have the while(1){} forever loop which kind of looks scary, it almost seems we are getting stuck in there...

__STATIC_INLINE void
SysCtrlSystemReset( void )
{
   // Disable CPU interrupts
   CPUcpsid();
   // Write reset register
   HWREGBITW( AON_PMCTL_BASE + AON_PMCTL_O_RESETCTL, AON_PMCTL_RESETCTL_SYSRESET_BITN ) = 1;
   // Finally, wait until the above write propagates
   while ( 1 ) {
      // Do nothing, just wait for the reset (and never return from here)
   }
}