DP83640: About RMII Interface

Hi Chunho,

Both RMII and MII are supported by RM device. By default, the MII is used by HDK HW settings. To use RMII, the following modifications should be make on HDK:

1. Populate R193 resistor (2.2kohms) to pull RX_DV up

2. Replace Y3 with a 50-MHz oscillator 

Refer below thread for more information,

(+) TMS570LC4357: MII and RMII design with LWIP - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

(+) TMS570LS1227: TMS570LS12HDK + lwIP library: RMII/MII question - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

(+) TMS570LC4357: MII and RMII design with LWIP - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

--

Thanks & regards,
Jagadish.

Dear Jagadish

Does it slave mode operating? How can i handle RMII_REFCLK (K19 pin of RM46L852)?

Should i have to populate R136 and do not insert R311?

Thanks

Cho

Hi Cho,

chunho cho said:

Should i have to populate R136 and do not insert R311?

No Need to do this modification according to old threads, you can keep them same and do only the two modifications i mentioned above.

--

Thanks & regards,
Jagadish.

Dear Jagadish

I'm confused.

Does it slave mode operating? 

You reviewed the following. I think that population of R136 and doing not insert R311 are right from your schematic review

And please recheck again below thread review is right or wrong

RM46L852: About Ethernet Interface - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

Dear Jagadish

Please answer the above question.

Thanks,

Cho

Hi Chunho, 

I am on vacation for last week, sorry for the delay.

chunho cho said:

Does it slave mode operating? 

Yes, it does.

chunho cho said:

And please recheck again below thread review is right or wrong

Yes, this modification also should need to be done.

--

Thanks & regards,
Jagadish.

Dear jagadish

Thanks for your reply.

Yes, this modification also should need to be done.

-> What does it mean? You mean that i should have to populate R136 and do not insert R311 for RMII on HDK.

Thanks

Cho

Dear jagadish

Please check above question.

Thanks

Cho