ST72F324BJ4T PF2 pin seems to have pullup with interrupt enabled

[tom_evans]

Posted on March 23, 2006 at 19:16

ST72F324BJ4T PF2 pin seems to have pullup with interrupt enabled

[tom_evans]

Posted on January 10, 2006 at 03:22

PF2's PFOR option bit is meant to enable interrupts on the pin and not a pullup (like it does on PF0 and PF1). When I set the option bit for PF2 it pulls high and will source about 60uA which it doesn't do with the option bit clear. This corresponds to an 80k resistor somewhere, which matches the expected range for the internal pullups on the other pins.

The test is as simple as configuring PF2 as an input, connecting a multimeter from the PF2 pin to ground and having it measure the current with the PFOR bit for this pin (0x04) on and off.

Can anyone with a development kit test this and prove me right or wrong?

Thanks,

[tom_evans]

Posted on March 23, 2006 at 19:16

PF2 does have a pullup.

This is now documented in the Rev 5 (Feb 2006) version of the Data Sheet, now available from the ST72324BJ4 page.