S32KのトピックRe: MDIO APIs in S32k344 RTD?

MDIO APIs in S32k344 RTD?

cmnxp — Mon, 18 May 2026 21:10:02 GMT

Hi there,

My custom board connects S32K344 EMAC's MDIO to SJA1110's SMI_AP interface. I'd like to configure SJA1110's internal 100BASE-T1 PHYs through MDIO interface, but I couldn't find any MDIO read/write APIs in real-time driver package. Can you tell me where those APIs are?

Thanks,

Charles

Re: MDIO APIs in S32k344 RTD?

PavelL — Tue, 19 May 2026 06:58:04 GMT

Hello @cmnxp ,

The MDIO access APIs are available in the S32K3 RTD, but they are provided under the GMAC driver rather than as a separate standalone MDIO module. In the GMAC RTD API, the relevant functions are Gmac_Ip_MDIOWrite() and Gmac_Ip_MDIORead().

For your specific use case with SJA1110 SMI_AP, please note that the internal 100BASE-T1 PHY subsystem is managed through a Clause 45 register map, so you will typically need the Clause 45 APIs - Gmac_Ip_MDIOReadMMD(), Gmac_Ip_MDIOWriteMMD().

Best regards,

Pavel

Re: MDIO APIs in S32k344 RTD?

cmnxp — Tue, 19 May 2026 12:46:58 GMT

Hi Pavel,

Thanks for your quick reply. So that means S32K344 only has one MDIO interface which is used for both EMAC and GMAC, correct?

Regards,

Charles

Re: MDIO APIs in S32k344 RTD?

PavelL — Tue, 19 May 2026 13:00:02 GMT

Hello @cmnxp ,

Yes, there's usually one SMI interface per EMAC/GMAC.

Best regards,

Pavel