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AM2432: MII configuration (MODE[2:0]) and CRS/COL

Part Number: AM2432

Hi Expert,

I would like to check with you about our MII configuration.

Q1) According to the datasheet below, I think that MODE[0..2] = 111 would be the option we can choose since it seems to cover all cases, but not 100% sure. Could you please let me know if 111 is okay or if any consideration is required to configure the mode?

Q2) Is CRS/COL supported? I was not able to find the pin for them. In my understanding, these are used for half-duplex mode. If we set 111 as the MODE, these are still needed?

I would appreciate it If you share your knowledge and guide on MII configuration. 

Best,

Moonil

  • Hi Moonil,

    I have assigned this thread to our Ethernet expert. You should be hearing from him shortly. If not, please feel free to ping here again.

    Regards,

    Prasad

  • Hi
    Which Ethernet PHY are you using?

    Both settings are not specifically related to MII and more HW related. 

    Auto negotiation enabled with all speeds and duplex has no connection with COL/CRS pin. If Half Duplex is needed COL/CRS pin is mandatory and you need at least one of COL or CRS pin to be connected to MII from PHY.

    Regards
    Dhaval

  • Hi Dhaval,

    LAN8740AI-EN will be used. 

    I found a setting for half-duplex in syscfg.

    our setting will be, 

    • pull-up for MODE[0:2] pin. So I think MODE[0:2] will be 111 and Auto-negotiation will be enabled by default.
    • uncheck "Half Duplex Enable" in syscfg as you can see captured image above.

    Q1) Could you let me know again if COL/CRS pin is required to be connected to AM243x in our setting above? the setting in syscfg will decide half duplex?

    Q2) I was not able to find COL/CRS pin of AM243x even, can you help me to find them?

    Regards,

    Moonil 

     

  • Hi Moonil,

    Not sure if you still need answers. Please let me know if its required. Below are some info attached:

    Q1) Could you let me know again if COL/CRS pin is required to be connected to AM243x in our setting above? the setting in syscfg will decide half duplex?

    Yes it needs to be connected. As mentioned in answer above for half duplex you will need this connection.

    Q2) I was not able to find COL/CRS pin of AM243x even, can you help me to find them?: TRM section  7.2.5.2.2.3.1(It is mentioned in table just above this section)

    BR

    Nilabh A.