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Wake up recovery from stop mode in MC9S12XS128(HCS12XS) microcontroller

Question asked by Sirish Madhusudhan on Jul 19, 2013
Latest reply on Dec 7, 2017 by


I am using MC9S12XS128 micrcontroller for automotive ECU, configured the processor to go to stop mode for low power consumption.

I have enabled the WUPE and WUPIE bits so that the controller wakes up from stop on arrival of CAN message.

I tried enabling them at initialization and also before going to sleep. In both cases it did not recover.
When I run the code, the ECU works well and goes to stop mode as expected, but is unable to recover when CAN message is received and ECU does not respond at all. Also all other Interrupts get disabled.

I tried using the Pseudo stop mode (enabled PSTP bit in CLKSEL) to see if that helps, but that too did not work.

I have used the following procedure to go to Stop mode:



__asm ANDCC #0x7F;

__asm stop;


Can anybody please help me reolve this issue?