How to enter Stop or Wait Mode?

[aguo1223]

       Hello  all,

                    how to enter Stop or Wait mode  when mcu is running?

                                                                PS:  MC9S12P128.

[RadekS]

For entrance into STOP and WAIT mode you should use directly CPU instructions.

You can use for example:

asm STOP;         //STOP mode

asm WAI;      //force the MCU into wait mode

In case of STOP mode, there is necessary also clear S bit in CCR register prior you use STOP instruction, otherwise STOP instruction will be executed as NOP.

So, you can use this code:

asm ANDCC #0x7F;  //clear S bit - enable the stop mode. If the S bit is not

                    //cleared then STOP instruction has no effect and is

                    //executed as a dummy instruction NOP.

asm STOP;         //STOP mode

Note: S bit will be restored during next reset.

[TomE · Accepted solution]

The purpose of this forum is to ask questions about how to use the forums, not how to use the products.

Please ask your question in the appropriate 8 or 16 bit forum, but SEARCH those forums first to see if someone else has already asked your question.

8-bit Microcontrollers

16-Bit Microcontrollers

These forums can be accessed directly under the "Products" section of the "Home" page.

Can one of the Administrators move this post please?

Tom

[aguo1223]

Thanks