Lpc2000

Hey Thomas,

The lpc2129 User Manual contains all the info u need on GPIO 
manipulation. Just note the following whenever you're manipulating 
Port0.

- You 'only' can read current GPIO pin states by reading the IO0PIN 
register. 

Variable = IO0PIN; 

- The User Manual defines IO0PIN to be a read-only register. 
IO0PIN = 0x0000 C700; // invalid statement (according to IAR compiler)

- IO0CLR,IO0SET writes is the only way of changing output pin states. 
- Writing 1's to the bits of IO0SET will make the corresponding pins 
High. 
- Writing 1's to the bits of IO0CLR will make the corresponding pins 
Low.

So with the statements u have:
IO0SET = 0x0000 C700  
IO0CLR = 0x0000 3800 //theres no need for this. Also note that:

- Writing 0's to IO0CLR/IO0SET has no effect on Port0. 

Using the IO0CLR/IO0SET registers facilitates a more disciplined 
approach towards output control.