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CC2540T: CC2540 Reset_N behavior

Part Number: CC2540T
Other Parts Discussed in Thread: CC2540

Hi Guys, 

in the user guide section on Page 70, Chapter 5, Document SWRU191F–April 2009–Revised April 2014, which we are questioning.  

“During reset, the I/O pins are configured as inputs with pullups (P1.0 and P1.1 are inputs, but do not have a pullup or pulldown). The RESET_N input is always configured as an input with pullup.”

 Our hardware and software tests show very clearly that this pull-up on RESET_N is not present. Can you clarify the behavior and if this is configurable?

Thanks and best regards

Jens 

  • Hi Jens,

    I can confirm that the CC2540 does in fact have an internal pull-up. This is present in all device states, and has a value of approximately 20k ohm.

    Without more details about your customer´s "hardware and software tests" I cannot comment on their observation.

    Regards,
    Fredrik