rcm6700 ethernet with transformerless

Question

We want to connect the ethernet port on RCM6700 to the switch chip and we want a design without transformer.

We want to connect directly, the RCM6700 ethernet port to one port on switch

Any hardware application?

Also we would need to disable the AUTO-MIDX, how can we do it?

BR

Jose Luis

Answer 1

The RCM6710 and RCM6760 have the transformer and Ethernet jack, but the RCM6700 and RCM6750 do not.

As you can see from the schematic, those modules put TX+/TX- and RX+/RX- on the header. What signals does the switch chip expect?

http://ftp1.digi.com/support/documentation/3001042102_a.pdf

And the schematic for the development board shows taking those signals directly into an Ethernet jack with integrated magnetics:

http://ftp1.digi.com/support/documentation/30011651-03_A_DEV.pdf

To disable auto MDIX, it looks like you can define DMAETH100_PXDR_AMDIX_EN as 0 in your project macros.

Comments

Thanks for your answer.

I am going to try explain better!!!

we want to connect two PHY (RCM6700 and other manufacture PHY) without magnetics.

We would like to know if we could connect directly TX+/TX- and RX+/RX- between both PHYs or we would need any passive components (resistors, capacitors, etc)

Thanks
Jose Luis

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I'm not sure if that would work or not.  I'd recommend searching elsewhere for a solution.  This question on the Electronics StackExchange has some good information, but it doesn't sound easy: https://electronics.stackexchange.com/q/90330