Lpc2000

Hi, I'm new to the LPC2138 and I'm using uVision3 as enviroment. I'm 
trying to debug my program code with the build in debugger. But I'm 
trying to figure out how i can write data to my serial input. And how 
I can simulate a break situation in my incoming data. This way I can 
check my software. I can already see my outcoming serial data with the 
serial 1 to 3 windows. Can someone help me with this?