MPC5777C-416DS FEC RMII Signal CLK_50MHZ

[martinstanzel1]

Dear NXP,

I have a question considering signal CLK_50MHZ necessary for using FEC in RMII mode.

According to MPC5777C EVB User Guide (Rev. 0, 08/2015) Pins 2&3 on Jumper J524 on MPC5777C-416DS must be connected in order to generate signal CLK_50MHZ.

In my setup this configuration does not work, the output signal CLK_50MHZ stays low instead of providing a 50MHZ clock. Is this jumper setting an error in the User Guide or is there a problem with my setup? Can you specify component "Y2"?

Thanks,

Stanzel

[martin_kovar · Accepted solution]

Hello Martin,

I checked directly on the board (MPC5777C - 516DS) and correct settings are:

J524 - position 1-2

J510 - position 2-3

In this case, I am able to measure 50Mhz on J510.3 pin. I n case I set J524 to position 2-3, there is no signal on J510.3. So, from my point of view, there is an error in User Guide.

Regards,

Martin