LPC2148 Internal Pull Ups - How to enable on P1.20

Development Boards MicroMod
1

Hi there,

I’m new to the forum and hoping to get some help with internal pull ups on the LPC2148.

According to the user manual (pin descriptions and electrical characteristics sections), there are internal pull ups on pins P1.16 to P1.20, however it’s ambiguous how to set these up. Have I missed something? Is is possible to enable these? I’ve searched pretty comprehensively online and haven’t been able to find anything to help.

Thanks very much in advance,

Avinash.

2

Hello Sidewinder,

I agree the documentation is on the sparse side regarding the pullups. i think we can infer that they are there to make the trace ports etc. work properly, and that NXP chose to “hard wire” them. I don’t see any documentation that suggests they can be disabled.

I have a couple of 2148 boards here. I’ll experiment and report back.

-Hugh