external reset and watchdog reset flags

[shaking928]

Does anybody know flags for external reset and watchdog reset for MC9S12XET MCUs? I cannot find them in MC9S12XEP100 Reference Manual.

[danielmartynek]

Hello @shaking928,

There are these reset vectors:

So, if the COP is the source of the reset, it will fetch the COP vector.

Please read the RM, Section 11.5.1 Description of Reset Operation

"External circuitry connected to the RESET pin should be able to raise the
signal to a valid logic one within 64 SYSCLK cycles after the low drive is
released by the MCU. If this requirement is not adhered to the reset source
will always be recognized as “External Reset” even if the reset was initially
caused by an other reset source."

Explained in details here:

https://community.nxp.com/t5/S12-MagniV-Microcontrollers/S12-FAMILY-DEVICES-COP-RECOGNITION-CONSIDER...

Simple S12XEP100 COP example is attached,

Regards,

Daniel