topic Re: How to implement the PFE clock configure in RTOS in S32G

How to implement the PFE clock configure in RTOS

waitewang — Tue, 10 Feb 2026 13:34:30 GMT

Dear Expert,

We are working on implementing the PFE (Packet Forwarding Engine) Ethernet driver for the S32G274A within a real-time operating system (RTOS). Since our RTOS does not have Linux’s clock framework or device tree infrastructure, we need to configure the required clocks by directly programming the hardware registers.

Could you please advise on how we can obtain the complete clock configuration logic or reference code for the PFE module? Any documentation, register-level examples, or best practices would be greatly appreciated.

Thank you very much!

Re: How to implement the PFE clock configure in RTOS

Joey_z — Wed, 11 Feb 2026 02:54:42 GMT

Hi,waitewang

Thank you for contacting us.

Sorry for that we do not provide the PFE+RTOS application to customer for reference.

Generally, the clock will be configured in the bootloader stage for Multi-core scenario, if you want to set the clock register on M core, you can try to refer to the S32G2RM.pdf of Chapter 24 Clock Generation Module.

Also, need to configure the partition for PFE.

Joey

Re: How to implement the PFE clock configure in RTOS

waitewang — Wed, 11 Feb 2026 06:22:35 GMT

Hello experts

I have another question about the clock of PFE module, as follow:

We referred to the GMAC driver’s clock configuration in the existing RTOS BSP. When initializing the PFE module, it is necessary to configure the MC_CGM_2 register block—specifically, to set up the TX clock for PFE_MAC_0, we need to configure the Clock Mux 1 Select Control Register (MUX_1_CSC) within this register group, as shown in the figure below.

In the SELCTL field of this register, a clock source must be selected. However, we are unsure how the clk_src_x identifiers described in the reference manual correspond to the actual hardware clock sources.

We found some related descriptions in the device tree files, but we don’t know how to map them correctly. Could you please clarify how clk_src_x in the manual relates to the real clock sources used in the system?

Re: How to implement the PFE clock configure in RTOS

Joey_z — Wed, 11 Feb 2026 06:47:05 GMT

Hi,waitewang

Thank you for your reply and informaiton.

Could you tell me you are using a single-core or multi-core scenario? initialization of clock can be post in the bootloader, why do you want to choose to configure the PFE clock on the RTOS？

Joey

Re: How to implement the PFE clock configure in RTOS

waitewang — Wed, 11 Feb 2026 07:13:27 GMT

Hello

I'm working in a multicore scenario. According to your reply, if the system is booted by U-Boot, does that mean the operating system doesn't need to configure the clocks?