DP83848I X1 CLKin and CLK_OUT

Other Parts Discussed in Thread: DP83848I

Hello,

Running the DP83848I in RMII mode.
Is it acceptable to feed the X1 pin of the DP83848I with a 50MHz clk (from an oscillator), and then use the CLK_OUT pin from the DP83848I as the clock in pin to the MAC?

Or does the 50MHz clk from the oscillator need to be fed to the MAC and the DP83848I (and not use the CLK_OUT pin on the DP83848I).

Thanks

over 9 years ago

0 Rob Rodrigues over 9 years ago

TI__Mastermind 19780 points

Hello Ro,

The DP83848 CLK_OUT pin should not be used as the RMII reference because timing delay between XI and CLK_OUT cannot be guaranteed. You may receive errors on your interface if you use this configuration.

The 50MHz reference should be distributed to the MAC and PHY.

Best Regards,

0 RD over 9 years ago in reply to Rob Rodrigues

Intellectual 280 points

OK. Thank you.

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DP83848I X1 CLKin and CLK_OUT