#pragma interrupt_handler uart0_rx_isr:12
void uart0_rx_isr(void)
{
//uart has received a character in UDR
com_in_buf[0]=UDR;
send_data(com_in_buf[0]);
}
//call this routine to initialize all peripherals
void init_devices(void)
{
//stop errant interrupts until set up
CLI(); //disable all interrupts
port_init();
uart0_init();