Should the RT1021 use the FreeRTOS port ARM_CM4F or ARM_CM7?

[rshipman]

Hi,

Which FreeRTOS port should the RT1021 be using?

The SDK demo projects use ARM_CM4F, but there are comments in there that say that CM7 r0p1 versions should use the ARM_CM7 port. (Also I think the original SDK demos used the CM7 one a few years ago?)

The RT1021 reference manual talks about the ETM Arm CoreSight™ ETM-M7 Revision: r0p1 Technical Reference Manual.

Please clarify which port to use.

Many thanks and kind regards.

[MultipleMonomials]

Hmm, in the past I used the debugger to inspect the registers of my MIMXRT1050 and it came back as a Cortex-M7 r1p1, even though the manual for this one also references "Arm CoreSight™ ETM-M7 Revision: r0p1".  So, I think that using the Cortex-M4F port is correct.

You can check it yourself by reading the CPUID register in the debugger (J-Link prints its value when connecting to the core, or you could read it manually).  Per here, the rightmost hex digit is the revision, and the sixth-from-the-right hex digit is the variant number.  For example, mine comes back as 0x411FC271, which would mean that it is r1p1.

[Gavin_Jia · Accepted solution]

Thanks @MultipleMonomials @rshipman for providing this method.

Yes, it is ARM_CM4F.