am using mdk 5.17 for LPC2388 programming. In the debug session, the GPIO of ports 3 and 4 are not changing. Am trying to set and clear the GPIO ports with a delay.Ports 1 and 2 only changes the values , if its programmed as legacy port, it wont work in debug when programmed as FIO. Some pins of port 3 and 4 wont change in the debug session(and trying to toggle all ports).. even got the same problem in earlier version of mdk.
For some strange reason I totally failed to guess what your code looks like.
And I also failed to figure out what debugging you have done - how you have compared what your program is doing with the documentation in the LPC23xx User Manual.