S32GのトピックRe: S32G399A - System timer module frequency

S32G399A - System timer module frequency

Matteo_Zini — Mon, 17 Mar 2025 09:46:43 GMT

Good morning,

I have an S32G399-RDB3 board with a setup derived from the GoldVIP package. The M7 binary and the Linux kernel images were changed, but the bootloader configuration is practically the same of the original configuration.

I'm using one of the system timer instances to collect measurements, and I wanted to ask whether there is a practical way to read the STM frequency without following the entire chain of clock signals.

Thank you.

Re: S32G399A - System timer module frequency

Joey_z — Mon, 17 Mar 2025 11:11:04 GMT

hi，Matteo_Zini

Thank you for contacting us.
May I ask why you want to read the STM frequency without following the entire chain of clock signals?
In addition, You can refer to the attachment to check the clock of M core STM.

Re: S32G399A - System timer module frequency

Matteo_Zini — Mon, 17 Mar 2025 11:41:17 GMT

Hi, thank you for the reply.
Because for example if you need to do it at runtime, there are multiple possible sources of the XBAR_DIV3_CLK clock and reconstructing the full chain is not trivial.

Re: S32G399A - System timer module frequency

Joey_z — Tue, 18 Mar 2025 01:57:58 GMT

hi,Matteo_Zini

Thank you for your reply.

There are multiple possible sources of the XBAR_DIV3_CLK clock, so you need to configure the same value of XBAR_DIV3_CLK for the M core and A core, to avoid conflicts.

Joey

Re: S32G399A - System timer module frequency

Matteo_Zini — Tue, 18 Mar 2025 14:32:23 GMT

I'm using Linux on the Cortex-A cores, so I'm not sure how to configure it.

Anyway, I would just need to understand the frequency to transform the ticks into seconds, not to set it to any specific value.

Thank you.

Re: S32G399A - System timer module frequency

Joey_z — Wed, 19 Mar 2025 04:01:59 GMT

hi，Matteo_Zini

Thank you for your reply.

If you want to know the exact STM timer time, you must know that the XBAR_DIV3_CLK default is 133.33Mhz, the frequency division factor CPS and CMP values.

Joey

Re: S32G399A - System timer module frequency

Matteo_Zini — Wed, 19 Mar 2025 08:28:59 GMT

Perfect, thank you for your help.