I am trying to send a UART signal but FSK modulated. I have created code to reduce the UART baud rate to 290, have created PCA frequency generation with a function called loopOne and loopZero. I undrstand that I need to call the loop functions to generate FSK inside the Interrupt, otherwise I get a horrible looking signal. What I am having trouble with, is figuring out how to hook up the UART to the interrupt lines for correct functionality. Here is how I have it right now:

P0.7TX is the transmission. I have wired it to P0.2 for the interrupt. I am unsure how or if that is correct, and what the c code would be to get the interrupt to call loopzero and loopone based on the value of P0.2. I have even gone as far as to add P1.5 wired to P07TX as digital and listen to that in the interrupt for loopone and zero, but the results are not any good. Can anyone give me some sample code that would call the interrupt, and that would be executed in the interrupt? Any help would be appreciated.