topic Re: Information on PCC INUSE Field in Kinetis Microcontrollers

Information on PCC INUSE Field

sean_dvorscak — Wed, 19 Mar 2025 00:18:08 GMT

Hello,

I am looking for more information on the INUSE bit in the PCC registers.

The field in the Reference Manual of the KE1, says the bit indicates whether or not the peripheral is being used.

I ran some code waiting to see if the INUSE bit would set for a peripheral that I know was being used, and it never set.

I then looked in the SDK for the KE1 processor in Clocks.h, and saw the description of CLOCK_IsEnabledByOtherCore. The description says it checks whether the clock is already enabled and configured by any other core, and it does this by checking if the INUSE bit is set.

So what is the INUSE bit really telling us? Is it being used by the Core that enabled it, or another core?

I am also confused on what it means by "Enabled and configured by another core"? I only have one Core in the Processor. Is this only for multi-core?

Re: Information on PCC INUSE Field

Celeste_Liu — Mon, 24 Mar 2025 08:56:10 GMT

Hello @sean_dvorscak ,

Thanks for your post. I have already understood your confusion. The description in the SDK is indeed strange. I have now contacted the NXP internal team to support us on this topic and I'm waiting for their feedback. I will keep you updated about any new relevant information.

BRs,

Celeste

Re: Information on PCC INUSE Field

Celeste_Liu — Tue, 21 Apr 2026 10:07:53 GMT

Hello @sean_dvorscak ,

The INUSE bit prevents race conditions on dual-core devices. While this IP is shared across platforms, the bit's relevance varies: it's meaningless (and should be reserved) for the single-core KE1x series, but essential for the dual-core K32 series.

Sorry for the inconvenience caused.

Celeste