SJA1105

[PrasanthKP]

We are using SJA1105 as ethernet switch and is interfaced to LAN7431 and AR8035 through RGMII interface. LAN7431 and AR8035 have MDIO MDC pins and no such pins found in SJA1105. Is any other parts with RGMII, MDIO, MDC pins or this SJA1105 enough for our requirement?. please refer the connection block diagram and suggest the design modification?. Is the connectivity in the block digram works properly or not?

[PrasanthKP]

Please refer this block diagram and where should be SPI connectivity from SJA1105 to the LAN7431 or to the AR8035 or to the SOC

[PetrS]

Hi,

SJA1105 SPI is used to load static configuration and to access all memory , control and status registers so should be connected to device that allows that, most probably your SOC.
1) seems LAN7431 does not have MDI interface, just MII/RGMII
2) SJA1105 operates as a slave device in transfer Mode 1
3) not sure of that

BR, Petr

[PrasanthKP]

Please refer this block diagram and where should be SPI connectivity from SJA1105 to the LAN7431 or to the AR8035 or to the SOC

[PetrS]

Hi,

yes, SJA1105 does not have SMI interface. Device is configured and all memory, control and status registers can be accessed via the Serial Peripheral Interface (SPI).
You can refer to SJA1110 (https://www.nxp.com/products/interfaces/ethernet-/automotive-ethernet-switches/multi-gig-safe-and-se...), but SMI is only used to access the 100BASE-T1 subsystem or to configure external PHYs from the internal Arm core.
A connection given in block diagram would work, I think.

BR, Petr