Hi, i was wondering if anyone could help me. I have modified the timer interrupt example that came with code composer studio, so that the prd register that sets the timer period can be modified by certain variables in the task function. Also i have changed the set up of the ISR so that the timer doesnt actually start and stop in it, so that the whole thing runs in real time rather than starting and stopping every time the ISR is called. For some reason this doesnt work, what ever i set the prd to, the output is always the same (Not time dependant), the calling of the ISR doesnt seem to change. Does anyone know why this is. In doing this do i need to change the timer structure? If it helps, the use of this is to create and output a realtime sine wave with the frequency of the sinewave being dependant on what the prd register is set to. The modifications to the task function is something like (changed it about so many times): /* Open Timer 0, this returns a pointer to a Timer Handle */ /* that will be used as an argument to other CSL functions */ mhTimer = TIMER_open(TIMER_DEV0, TIMER_OPEN_RESET); printf("Initial\n"); TIMER_getConfig(mhTimer,&myTConfig); printf("TIMERCONFIG TCR:%x PRD:%x\n",myTConfig.tcr, myTConfig.prd); /* Write configuration structure values to Timer control */ /* registers. */ // myTConfig.prd=timer_period; myTConfig.prd=0x0000u; TIMER_config(mhTimer, &myTConfig); printf("After setting\n"); TIMER_getConfig(mhTimer,&myTConfig); printf("TIMERCONFIG TCR:%x PRD:%x\n",myTConfig.tcr, myTConfig.prd); If anymore information is needed let me know. Would appreciate any help. Thanks for your time, Alex Bluett.