Content originally posted in LPCWare by DiligentMinds.com on Thu Aug 30 18:38:07 MST 2012
All of the IO pins that are configurable GPIO's are configured by default as inputs with a pull-up while a reset is active-- and they will stay that way until you program them to do something else. There is a power-on reset that is generated internally in the chip, so the GPIO's will be in their default configuration (as above) when the chip is first powered on.
--Ken
