S32KのトピックRe: S32K388 CANNOT PING ETHERNET RGMII GMAC0

S32K388 CANNOT PING ETHERNET RGMII GMAC0

vinmotion — Wed, 07 Jan 2026 01:29:12 GMT

Hello engineers,

I'm encountering an issue while testing the RGMII GMAC0 Ethernet interface on the S32K388 evaluation board—I am unable to successfully ping the assigned IP address. Starting from the standard lwIP example (which uses GMAC1), I have modified the PINS multiplexing to route signals to GMAC0, updated the CLOCK accordingly, adjusted device init function and chang the PLATFORM in Mcal Components tab . Despite these changes, the link does not establish properly, and ping attempts fail.

Could you please review my modifications or test the GMAC0 interface on your side using the attached zip file (containing the modified project)? Any insights into potential configuration differences between GMAC0 and GMAC1, PHY initialization issues, or known limitations with GMAC0 in the lwIP examples would be greatly appreciated.

Thank you for your assistance

Re: S32K388 CANNOT PING ETHERNET RGMII GMAC0

PavelL — Wed, 07 Jan 2026 11:32:36 GMT

Hello @vinmotion ,

I assume that this query is a duplicate of this thread:

Solved: S32K388 RGMII GMAC0 ethernet cannot ping - NXP Community

Best regards,

Pavel

Re: S32K388 CANNOT PING ETHERNET RGMII GMAC0

vinmotion — Wed, 07 Jan 2026 12:42:06 GMT

Thank you Sir , but can you confirm that when using RGMII GMAC0 with S32k388 we modify device init function example become like this right::

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,

Re: S32K388 CANNOT PING ETHERNET RGMII GMAC0

PavelL — Wed, 07 Jan 2026 13:08:19 GMT

Hello @vinmotion ,

As you can see, not all rows in the code snippet are related for GMAC0. This code is used on all my examples - it fixes GMAC0 as well as GMAC1.

Best regards,

Pavel