topic S32K3 - PIT Clock in S32K

S32K3 - PIT Clock

ssean — Fri, 09 May 2025 05:35:22 GMT

Hello.

I am testing the Iseled example code.
PIT_0 and PIT_1 are connected to AIPS_SLOW and run at a 30 MHz clock.
Why is the GptChannelTickFrequency from the GPT module outputting as 60 MHz?

BRs,

Sean Sung

Re: S32K3 - PIT Clock

danielmartynek — Fri, 09 May 2025 07:29:32 GMT

Hello @ssean,

The ClockReferencePoint is configured in the MCU driver:

By the way, there is no clock option with CORE_CLK = 60MHz (RM, Section 24.7.2 System clocking configurations).

We recommend using one of the clock options.

At least the ratios between the clocks must be set to one of the clock options.

Regards,

Daniel

Re: S32K3 - PIT Clock

ssean — Sun, 11 May 2025 23:17:49 GMT

Dear @danielmartynek

There is no reference point for AIPS_SLOW_CLK in ISELED example project.

So I added like below.

The GptChannelTickFrequency of the GPT module is still outputting 60 MHz.
Shouldn't the GptChannelTickFrequency of the GPT and PIT modules be based on the AIPS_SLOW clock?
What configuration determines this output frequency?

I have already reviewed the use of the 60 MHz Core Clock.

https://community.nxp.com/t5/S32K/S32K312-Core-Clock/td-p/1978738

Is there any invalid setting value in my configuration?

BRs,

Sean Sung.

Re: S32K3 - PIT Clock

danielmartynek — Mon, 12 May 2025 08:00:24 GMT

Hello Sean,

The ratios between the clocks seems to match this option: RM, Table 161. Option F - Operation in 1:1 mode with CORE_CLK and AIPS_PLAT_CLK at same speed.

However, can you use CLKOUT_RUN to confirm it?

Regards,

Daniel

Re: S32K3 - PIT Clock

ssean — Mon, 12 May 2025 23:20:45 GMT

Hello @danielmartynek

Is this setting related to the Gpt module's GptChannelTickFrequency output?
Could you check the GptChannelTickFrequency first?

Clock setting is below.

BRs,

Sean Sung

Re: S32K3 - PIT Clock

danielmartynek — Tue, 13 May 2025 07:14:28 GMT

Hello Sean,

You need to use McuClockReferencePoint_1

How is GptClokcReferencePoint_0 configured in GptDriverConfiguration?

Re: S32K3 - PIT Clock

ssean — Tue, 13 May 2025 07:18:26 GMT

Hello @danielmartynek

I made mistake that.

I was able to solve it using the method you suggested.

BRs,

Sean Sung