How could I create a loop
that will only execute when an event happens

I would like to do something like this

JNB TI,$ ;Wait for TI to go high
CLR TI ;Clear TI
MOV SBUF,A ;Send the accumulator out the serial port

Only using C language -- not asm

I am trying to send data using the serial port, and I think I may be overwritting bytes. I would use a delay function after each byte is sent, but the entire data packet (4 bytes) must be received in 20ms

thanks

Casey