EVAL-ADIN1100 media converter

Hi,

On the EVAL-ADIN1100 board the ADIN1200 can be configured over the MDIO bus, which can be done in one of two ways. Through the Cortex MCU which is accessible through the uUSB connector, or on the MDIO bus directly through the external MDIO host connector.

Best Regards,

Mark

Dear Mark, 

Thank you so much for your prompt reply. I do have a follow up question because it puzzles me how this operates.

When I configure EVAL-MDIN1100 in media converter mode using the CFG switches, the ADIN1100 operates in media converter mode automatically using the on board ADIN1200 as external PHY but who configures the ADIN1200 in this mode? Is it the on board MCU through the MDIO interface or the AD1100 via the RGMII interface?

We're looking to implement a standalone media converter in our end application and I'm getting puzzled by the partial guidance. Is it possible to have ADIN110 & ADIN1200 based media converter that will operate without any MCU intervention or should we have an MCU that will configure the PHY on boot and then let it operate via RGMII?

I will really appreciate your thoughts specifically on this configuration.

Thank you very much!

Hi,

The ADIN1200 is not configured over RGMII, it is configured over the MDIO bus. For media converter applications it is recommended that an MCU is used to configure the ADIN1200 over the MDIO bus with the following writes.

1. RMII RX/TX interfaces are not functionally compatible (not supported by the RMII specification), so by default aren’t intended to be connected back to back directly. However, there is a bit field provided in the ADIN1300 which allows configuration of back to back mode with the RMII interface. If connecting the ADIN1300 to another ADIN1300 (or ADIN1200), set GE_RMII_CRS_EN to 0 in the GE_RMII_CFG register. This will disable CRS encoding on CRS_DV, so it can be connected to TX_EN.
2. In 10BASE-T mode and with any of the MAC interfaces, the 10BASE-T receiver can remove several preamble bits, so the RX data would have <7 preamble bytes. This could cause problems for the remote end receiving the frame. To avoid any issues, enable the 10BASE-T RX preamble re-generation by setting the GE_B10_REGEN_PRE register (address 0xFF38) to 0x1. This isn’t captured in the current version of the ADIN1200 datasheet, but will be included in a future revision. For now a description of this register can be found in the ADIN1300 Datasheet.

Best Regards,

Mark

Got it, thanks a lot Mark!

Got it, thanks a lot Mark!