topic Re: freesrtos+MMAU+KM34Z in Kinetis Microcontrollers

freesrtos+MMAU+KM34Z

nickng — Fri, 01 Jun 2018 08:33:14 GMT

Hi ,

If I want to use the freeRTOS with MMAU in a KM34Z MCU. Do I need to some port.c modification in order to use MMAU without troubles?

e.g the store /restore the MMAU registers?

Thanks!

Re: freesrtos+MMAU+KM34Z

jingpan — Mon, 04 Jun 2018 03:11:06 GMT

Hi Nick,

No, you do not need to do any thing to enable MMAU. To minimize power dissipation, the design supports an architectural clock gate for the entire module, that is, the MMAU is only clocked when responding to bus requests to its programming model or is busy performing a calculation.

There is a MMAU demo in KM34 sdk, please find it in \boards\twrkm34z75m\driver_examples\mmau.

Regards,

Jing

Re: freesrtos+MMAU+KM34Z

nickng — Mon, 04 Jun 2018 06:20:04 GMT

Hi Jing,

Thanks for your reply!

My question is focusing on the context switching ( or interrupts) of the RTOS with that specific MMAU registers.

For a bare metal system, with can use the pair of store and restore action of those mmau register. Do I need to do the same on the port.c ?

here are the store/restore pair :

Re: freesrtos+MMAU+KM34Z

MarMi — Mon, 04 Jun 2018 07:36:03 GMT

Hi Nick,

from MMAU initialization point of view as Jing explained above - no special steps needed.

Yes MMAU register context save / restore would have to be handled by FreeRTOS if MMAU is used in more tasks. In this case, most likely, portasm.s would have to be be extended by saving/restoring MMAU registers.

If you plan using MMAU in single task then no saving/restoring MMAU is required and use can use current FreeRTOS files.

Kind regards,

Martin M.

Re: freesrtos+MMAU+KM34Z

nickng — Tue, 05 Jun 2018 02:01:28 GMT

HI Martin,

Thanks or the answer.

By the way, the FreeRTOS embedded most os the asm code in port.c as well.