Hi,
The IO0PIN register was a defined as a read only register in the header file of LPC2142. But the datasheet says it is a read and write register. I changed the header file to make the register read and write. I issued a instruction like IO0PIN_bit.P0_2 ^= 1 in a sub function, I dont see any changes in the output port. However if the same instruction is given in the main function, it works fine. What could be the problem?