RTOS/CC2640: CC2640 Watchdog Implementation Stack 1.40.00.45 suggestions for triggering callback only if system hangs

Atul W

Part Number: CC2640

Tool/software: TI-RTOS

Hi All,

I have implemented watchdog based on this thread :http://e2e.ti.com/support/wireless-connectivity/bluetooth/f/538/t/786524?RTOS-CC2640-Watchdog-timer-not-working#pi320995=2&pi320995filter=all&pi320995scroll=false

here callback is called every for preset period, I want to trigger it when system hangs where do i need to change the code my.?

My part of code is as follows

Board file:

const WatchdogCC26XX_HWAttrs watchdogCC26XXHWAttrs[COIN_v4_R2F_WATCHDOGCOUNT] = {
{
.baseAddr = WDT_BASE,
.intNum = INT_WDT_IRQ,
.reloadValue = 150, /* Reload value in milliseconds */
},
};

Callback function:

void watchdogTimerCallback(UArg handle)
{
Watchdog_clear(WatchdogHandle);
// Perform the equivalent of a PIN Reset (hard reset).
// The cc26xx system has not been design to handle soft reset.
// Making a soft reset can make the system unstable.
// All soft reset needs to be replace by Hard reset.

SysCtrlSystemReset(); // SysCtrlSystemReset() instead of HAL_SYSTEM_RESET()
}

initialization:

static Watchdog_Handle WatchdogHandle=NULL;

#define WDT_TICKS (200)

void init_watchdogfun()

{
Watchdog_Params params;
uint32_t tickValue;

Watchdog_init();

Watchdog_Params_init(&params);
params.resetMode = Watchdog_RESET_OFF;
params.debugStallMode = Watchdog_DEBUG_STALL_ON;
params.callbackFxn = watchdogTimerCallback;
WatchdogHandle = Watchdog_open(COIN_v4_R2F_WATCHDOG0, &params);

tickValue = Watchdog_convertMsToTicks(WatchdogHandle, WDT_TICKS);

Watchdog_setReload(WatchdogHandle, tickValue);

}

Thanks in Advance

Atul

over 6 years ago

0 J Lindh over 6 years ago

TI__Guru 57865 points

Hi Atul,

Could you please describe the problem you are facing?

0 Atul W over 6 years ago in reply to J Lindh

Expert 1270 points

Hello J Lindh,

Thanks for the response ..!!!

With the code mentioned above in my query,the watchdog callback is called every-time for the defined period ,i want the watchdog to trigger the callback only if the Hang occurs ,what do i need to change in the above code .?

Could you please guide me in this ..!!!!

Thanks in Advance

Atul

0 Aslak N. over 6 years ago in reply to Atul W

TI__Mastermind 23440 points

Hi Atul,

If you don't want the callback to be called you need to clear the watchdog somewhere in you code _before_ the timeout occurs. How should the watchdog know whether your code has stopped working or not? You have two options at least, 1) in the callback check some global variables that would tell you if the code works or not, clear watchdog if this is the case otherwise let it time out again to force WDT reset (or reset immediately), 2) periodically clear the watchdog from your main process so that the callback is never invoked.

Please see the watchdog example:
http://dev.ti.com/tirex/explore/node?a=krol.2c__3.10.00.15&node=AM9TZseFks61H2S0v0GOcQ__krol.2c__3.10.00.15

And the TI-RTOS Driver documentation for Watchdog:
http://dev.ti.com/tirex/explore/node?a=krol.2c__3.10.00.15&node=ADfS7ixpgUmHy56H6NON4Q__krol.2c__3.10.00.15 (see the two watchdog links at the bottom of the first table)

Best regards,
Aslak

0 Atul W over 6 years ago in reply to Aslak N.

Expert 1270 points

Hi Aslak,

thanks for the response ...!!!!!

i have made the changes and its working.

when system hangs,I am calling one function in watchdog callback which stores the buffer contains of application to external flash before watchdog reset and after reset i want to retrieve the buffer contains .

But when that function is called its not storing any buffer content to external flash and system gets stuck and as Watchdog reset is on it resets the system without executing external flash commands.

So my question is:

1. When Watchdog is enabled will it allow the code to write into flash?

2.if not how can i store the buffer contains of hanged application in such case?

Please Suggest some solution to this issue ...!!!

Thanks in Advance

Atul

0 Aslak N. over 6 years ago in reply to Atul W

TI__Mastermind 23440 points

Hi Atul,

Watchdog callback is executing in Hwi mode where none of the drivers and almost none of the RTOS APIs are designed to work. This includes SPI driver for external flash.

You have a couple of options, but the simplest is perhaps to use the AUX RAM as storage during the WDT reset. It's not really designed to be retained during reset, but to my knowledge it tends to work out OK. See http://dev.ti.com/tirex/explore/content/simplelink_cc2640r2_sdk_3_10_00_15/docs/blestack/ble_user_guide/html/ble-stack-common/aux-as-ram.html#

You could also potentially implement a SPI interface in the Sensor Controller core and have it write to external flash during this time.

Best regards,
Aslak

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RTOS/CC2640: CC2640 Watchdog Implementation Stack 1.40.00.45 suggestions for triggering callback only if system hangs