Dual ethernet on iMX6ULL with Viola carrier board

Technical Support
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1

Hello I want to make an dual ethernet on iMX6ULL without use an USB/ethernet card.

I want to use the Dual Ethernet Carrier Board documen
colibri_vfxx_2nd_ethernet_reference_v1.0a_schematics (1).zip (320.0 KB) on Viola Carrier Board.

So for the prototype I want to have the output of the second ethernet on X9 on Viola Carrier Board but SODIMM 89 et SODIMM 71 are not on X9 so 89 and 71 can by change with another Pin ?

2

Hi @Alex_cira, how are you?

Welcome to our community :rocket: ! Sorry for the delay in reaching back to you. Do you have only the Viola Carrier Board or would you be able to use the Evaluation Board for test purposes? At first, if the pins are not exposed on the Board as you talk about SODIMM 71 and 89, you’ll have a hard time trying to use them. Depending on how you connect jumpers on the Viola to the SoM this may not work.

Moreover, if you look at the datasheet for the https://docs.toradex.com/104446-colibri-arm-som-imx6ull-datasheet.pdf you’ll find in table 5-5 the RMII signals for this module. You can see a note saying they’re not family compatible; therefore, you can’t simply connect the same pins as stated on the schematic you uploaded. You can see, for instance, that the RMII_TXEN is on SODIMM 30 on the iMX6ULL while it’s on SODIMM 85 for the VFXX. You can see the same for pins like SODIMM 184 of Colibri iMX6ULL being the RMIOO_MDC instead of the SODIMM 71. The tables also show the only pins that are able to deal with this interface.

The only line that could have more than one possibility is ENET_REF_CLK1, which can be used with SODIMM 19, 67 or 8.

I’d also suggest you have a look at the following links:
https://docs.toradex.com/102491-colibri-arm-carrier-board-design-guide.pdf → Carrier Board Design Guide
pinout.toradex.io → Pinout designer. This will help you check if any pins you’d need to use for this would conflict with other interfaces.
Device Tree Customization | Toradex Developer Center → Talks about device tree customization.

Please tell us if you’d still need more information

Best regards,

3

Hello @gclaudino.tx ,thank for the reply.

I look at the link you post and check the PIN of VF50 and IMX6ULL.
So I made table pin for the two, is the PIN for the second ethernet of IMX6ULL right?

PIN VF50 FUNCTION PIN IMX6ULL
98 MDIO 180
101 CRS_DV 178
103 RXD1 63
79 RXD0 55
97 RXER 104
85 TXEN 30
87 RESET_OUT 87
89 CLKOUT_OUT 19/67/8
71 MDC 184
59 TXD0 188
67 TXD1 73

And if it right I don’t find MDIO, MDC,TXD0 and TXD1 on X9 it is doable to have the différent signal in output PIN like X9.

4

Hi @Alex_cira,

Thanks for the update. This table seems indeed right.

However, if these pins are not exposed on the X9 I can see only a few options for you to use a second ethernet interface:

  1. Either change your carrier board to another one from Toradex that has these interfaces exposed. You may be able to do and test it with the Evaluation Board;
  2. Either create your own custom carrier board.

I don’t recommend connecting the pins directly from the SoM as it may not work and you may compromise the pins while trying to solder.

Please tell me if this would work for you.

Best regards,