Can COL, CRS and RX_ER on MII be unused on STM32F407 ?

[scott239955_stm1_stmicro_com]

Posted on December 17, 2013 at 22:25

We need (don't ask why) to use a PHY which does not have COL, CRS or RX_ER pins.  Can these be tied off to appropriate logic levels on the STM32F407xx we're going to be using and still result in proper operation?

Thanks,Scott #stm32 #stm32f407-mii #rx_er

[Tesla DeLorean]

Posted on December 17, 2013 at 22:54

Pretty shallow pool here, suggest you contact an FAE.

Plan B would be to modify an existing board, or just not configure/connect the pins (AF mux), and try it.

[scott239955_stm1_stmicro_com]

Posted on December 17, 2013 at 22:58

Thanks, I'll do that!

Scott

[derek]

Posted on May 13, 2014 at 10:55

Scott, did you ever get an answer from STM?   I'm connecting the STM to RMII switch (no need for RX_ER signal because of store-and-forward).   I'm want the RX_ER pins for a another function, but can't really tell from the STM32 datasheet what will happen if an input is not assigned to an alternate function. 

[doebber2]

Posted on October 07, 2014 at 14:06

Hi Scott,

I have the same question. Did you get an answer or have a solution for the ''MII-Lite'' connection?? regards Marc