Matrix user forums

How can I disable internal pull ups in PORTA . Chip 16F88

Risto

Hi.

There are no internal pull-ups on PORTA for the 16F88. They only exist on PORTB and are all off by default when you power-up. The pull-ups are only enabled when the port is configured as an input and you expressly set the applicable option register to enable them.

It sounds like something else is taking your port pins high... external pulls or driven high as outputs perhaps?


All the best,

Brendan

I´ll try to say. Output states for PORTA and PORTB should be 0 and HiZ .Normally they are 0V and 5V and they both are active. I'd need 0V avtive and HiZ

Hello,

To output a logic 0 to the port pin you can use the output icon in either port or bit mode depending on what you need to pull low.

To switch the pin to high impedance mode you can use the input icon again in port or bit mode.