I doubt cc2530 IR generation and I had saw the RemoTI demo (hal_irgen.h/h) but have something done't understand.

I see this "The output of Timer 1 channel 1 is ANDed with that of Timer 3 channel 1 to form the IR output"(IR Signal Generation and Learning).And I also saw in hal_irgen.c used "IRCTL = 1; " to enable IR generation or used T3 ch1 to enable IR generaion? I have see that a lot of people isn't used  IRCTL = 1.I doubt that is other way to enable gneration IR signal?