DP83848 Tx Behavior During Reset

John Jepson

Hi,

Would you be able to tell me how the TD- (pin 16) and TD+ (pin 17) outputs behave while the RESET_N (pin 29) or PWR_DOWN (pin 7) inputs are asserted?

Thanks,

John

over 11 years ago

0 Patrick OFarrell over 11 years ago

TI__Mastermind 31600 points

With RESET_N or PWR_DOWN asserted, the transmit pins should be inactive. The pins should not generate any signaling in this state.

Patrick

0 John Jepson over 11 years ago in reply to Patrick OFarrell

Prodigy 80 points

Hi Patrick,

Thanks for your reply. In that case do you know what the inactive state of the Tx pins should be? i.e pulled high / low or Hi-Z?

Thanks again,

John

0 Patrick OFarrell over 11 years ago in reply to John Jepson

TI__Mastermind 31600 points

John,

The TX pins should be Hi-Z. However, the pins should connect to 50 Ohm termination resistors that are in turn connected to the 3.3V supply. As a result, the pins should sit at 3.3V due to the termination resistors.

Patrick

0 John Jepson over 11 years ago in reply to Patrick OFarrell

Prodigy 80 points

Hi Patrick,

That's great, thanks!

John

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DP83848 Tx Behavior During Reset