topic S32K388 RGMII GMAC0 ethernet cannot ping in S32K

S32K388 RGMII GMAC0 ethernet cannot ping

vinmotion — Mon, 05 Jan 2026 05:19:17 GMT

Hello engineers,

I’m facing an issue while bringing up GMAC0 on the S32K388.

I have already configured and enabled the 14 required GMAC0 pins, but I’m still unable to ping the device from my laptop, im new to NXP so dont know the flow or any else where to config to use rgmii GMAC0 on S32K388

Could you guys please help review my test project and advise what might be missing or incorrectly configured?

Any guidance would be greatly appreciated.

Re: S32K388 RGMII GMAC0 ethernet cannot ping

PavelL — Mon, 05 Jan 2026 14:49:11 GMT

Hello @vinmotion ,

I reviewed your project and here are my findings:

Pins look correct
Clocks are not correct. Please fix it based on picture below. If you require 100Mbps just change dividers and/or manual setting of yellow numbers: 125MHz -> 25MHz and 250MHz -> 50MHz. Also set PLL AUX accordingly to the picture.

Replace DCMRWF settings in device_init() by these rows:

/* Bypass MUX_7 manually, GMAC0_RX_CLK is derived directly from input pin. */
IP_DCM_GPR->DCMRWF3 |= DCM_GPR_DCMRWF3_MAC_RX_CLK_MUX_BYPASS(1u);

/* Bypass MUX_15 manually, GMAC1_RX_CLK is derived directly from input pin. */
IP_DCM_GPR->DCMRWF4 |= DCM_GPR_DCMRWF4_MAC2_RX_CLK_MUX_BYPASS(1u);

/* Enable GMAC1_TX_RMII_CLK loopback manually. */
IP_DCM_GPR->DCMRWF2 |= DCM_GPR_DCMRWF2_MAC2_LOOBPACK_CLK_SEL_MASK | DCM_GPR_DCMRWF2_MAC2_TX_RMII_CLK_LPBCK_EN_MASK;

/* Configure GMAC1 to RGMII mode manually. */
IP_DCM_GPR->DCMRWF4 |= DCM_GPR_DCMRWF4_MAC2_CONF_SEL(1u);

Optionally, you may comment out rows 622 to 642 in test.c to remove limited time of lwIP example.

Best regards,

Pavel

Re: S32K388 RGMII GMAC0 ethernet cannot ping

vinmotion — Tue, 06 Jan 2026 02:24:22 GMT

Thank you Sir

im trying to use the lwIP example on the S32K388 , but im running into build/compile errors and i'm not sure why i'm unable to get GMAC0 Ethernet (RGMII) working

Would it be possible for you to share a working zip project for GMAC0 RGMII on S32K388.. That would really help me debug my setup, now im waiting to order adapter ethernet for S32k388

Thanks a lot for your support

Re: S32K388 RGMII GMAC0 ethernet cannot ping

PavelL — Wed, 07 Jan 2026 06:51:43 GMT

Hello @vinmotion ,

If you have build error, sharing the project will not help.

Please check your installation setup - here's my setup:

S32 Design Studio 3.6.1

S32 Configuration Tools R1.8.0 NPI data package for S32K388

S32K3_S32M27x Real-Time Drivers AUTOSAR R21-11 Version 6.0.0

FreeRTOS Update-site for S32K3 version 6.0.0 CD1

TCPIP_STACK for S32K3XX version 3.0.0

Best regards,

Pavel

Re: S32K388 RGMII GMAC0 ethernet cannot ping

vinmotion — Wed, 07 Jan 2026 07:01:26 GMT

Thank you Sir , i use all your config with clock but still cannot ping test with GMAC0 Rgmii for s32k388, hopefully anyone can please test ping because i got the board but not have the adapter ethernet yet

Re: S32K388 RGMII GMAC0 ethernet cannot ping

PavelL — Wed, 07 Jan 2026 08:54:34 GMT

Hello @vinmotion ,

I successfully brought up example lwip_FreeRTOS_s32K388, baremetal shall be about the same.

It's not clear from the description, but I assume that you use S32K388EVB-Q289.

I check your last project:

Pins look correct. Only MDIO shall be set as Input/Output, but this is not important for now.
Clocks looks correct.
Platform - IRQ's handlers should be defined (I didn't notice before that handlers were undefined):

Eth_43_GMAC - need to be set to RGMII 1G, Eth indexes should be 0 ( = GMAC0)

S32K388EVB-Q289 - Jumper J361 shall be closed

Best regards,

Pavel

Re: S32K388 RGMII GMAC0 ethernet cannot ping

James_Zhang_SE — Tue, 13 Jan 2026 01:40:23 GMT

Hi Pavel,

I have adjusted the project as you have mentioned in the other posts and this thread. However, I'm still not able to ping from PC after making all these changes. I'm using a RAD-MOON2 as the media converter. Can you kindly check if I'm missing anything in my project or what else do I need for the setup?

Re: S32K388 RGMII GMAC0 ethernet cannot ping

PavelL — Tue, 13 Jan 2026 12:47:06 GMT

Hello @James_Zhang_SE ,

Please note: Once an answer is marked as a solution, the original query is no longer actively tracked in our system. I only receive subscription emails for updates, and those can occasionally be missed.
If you need further assistance, the best approach is to create a new query.

I checked your latest project and TX_CLK should be set to output - after the change, your example works on my board well.

Please check on RAD MOON2:

Slave mode is set (S32K388 EVB: U97 - bit 7 in middle position -> CONFIG 6 open -> Master)
MacSec is disabled
Correct speed 1000Mbps is set

Best regards,

Pavel