Hi, I'm beginner in software-develop for µcontroller and i have a question to programm ISR: I can initialise the UART for writing data, but I want to observe incoming data. For that I need an ISR. I declared my ISR with "void rdx0_isr (void) __attribute__ ((interrupt));" When an interrupt depends .. no jump to rdxo_isr happens. I've no idea what's the problem. I programm for LPC2106 with Keil µvision (GCC3.3.1) using the unmodified startup.s for Phillips processors and the recommendet linker script file. maybe somebody has an example projekt for UART I/O. Or some tips for programmming. thanx..