topic Re: Backup Watchdog in ColdFire/68K Microcontrollers and Processors

Backup Watchdog

Dekabrist — Wed, 13 Feb 2013 08:26:34 GMT

Hello, all

My board run under BDM and Backup Watchdog Timer init with Processor Expert bean. But, when I break debug (stop Run) Backup Watchdog Timer NOT reset MCU and I read WCNTR = 0000, even when my programm write 0x5555 0xAAAA to WSR. My configuration:

CLKMOD[01] = 01 (CLKMOD0 pin have pullup resistor, XTAL pin NOT have pullUP resistor)

BWCR (CLOCK MODULE) = 0x00 - 32 MHz from bus

WCR = 0x0003

WMR = 0xFFFF - 8388,48 ms timeout

Init function:

void Wtm1_Init(void)

{

/* WMR: WM=0xFFFF */

setReg16(WMR, 0xFFFFU);

/* WCR: ??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,STOP=0,WAIT=0,DOZE=0,??=1,EN=1 */

setReg16(WCR, 0x03U);

}

Can I check software reset in the debug mode?

P.S. I use CW version 5.9.0 build 5293

Thank for answer

Re: Backup Watchdog

DavidS — Wed, 27 Feb 2013 23:30:36 GMT

Hi Sergey,

The ColdFire BWT is good for production application but not good for debugging mode. The BWT clock continues clocking even when you hit a breakpoint (which stops the core but it not the same as implementing a STOP instruction).

You could use the internal (slower) clock rather than the 32MHz to increase the timeout period.

Regards,

David

Re: Backup Watchdog

Dekabrist — Fri, 01 Mar 2013 08:15:51 GMT

Hi David

I activate toolbutton "break " in the debug mode and wait more than BWT timeout - BWT must reset MCU under this conditions? I make sure that my BWT work.

Sergey