LPC1114 GPIO voltage levels

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by vladimirro on Sat Jun 20 13:07:18 MST 2015
Hello again

Let me introduce another problem I faced with LPC1114.
I tried to implement PWM and I noticed that the low state never reached 0V. It varied from 400mV to 600mV.

Then I set one of the GPIO to logic low and it turned out that my uC doesn't output 0V but 0,4-0,6V...
I couldn't find any information about voltage levels of GPIO in LPC1114 but I guess logic low should be 0V.
I probed the GND pin and it is 0V.

What can be a reason of such behaviour?