Hello community
I've a problem. I use this microcontroller since a lot of year, but lately there's something wrong. I use BKGD pin as I/O pin, so at the beginning i set SOPT1 register
SOPT1 = 0b00000000;
Sometimes when I power up the circuitry, the pin show a 2.3V voltage (I use 5V as power supply) and my program does not start. I can't understand why! The circuit I use is very similar to one I use in other product in which this fact has never show!
I use an external resistor as pullup to 5V on the BKGD pin as in the image I've attached. Then a 1K resistor goes to a red led that goes to GND.
Does anybody know how is it possible? Where I'm wrong?
As I told before, this scheme is used since some years but only now I've problems.
You seem to have an external pull up. Are you sure you don't also have an pull-down in the MCU (i.e., bit PTAES4=1)?
No pull down setted or enabled in MCU. PTAPE = 0b00000000;
As I mentioned before, I've a situation as in the image below: a pullup (10K) to 5V, a resistor (1K) with a red Led diode. I know that the diode can be polarized from 5V and 11K, but i don't know why it never happened in the past!