Now, there is a problem with the design as TI has presented it, and some developers who are more experienced MSP430 software designers may have already seen it. The problem is that, MSP430 devices are typically used in applications that demand very low power consumption. If the SYS/BIOS heartbeat is defined to be 1 KHz, then that means that the MSP430 will need to wake up from low power mode once every millisecond in order to service this interrupt. That might be OK if real work needs to happen every millisecond, but if, for example, the developer only has a semaphore that times out after, say 5 milliseconds, then that means ones device will need to be pulled out of low power mode an extra 4 times in which it does nothing but increment the timer module and go back to sleep. For the developer who is thinking that one could deal with this by simply changing the BIOS heartbeat to 5 milliseconds, think about the pitfalls and complexity of that approach. Anyone who changes the timeout value in a, for example, Semaphore_pend call, will also need to realize that one needs to change the heartbeat rate to accommodate it, making ones code very complex and unmaintainable. It is these kind of complex interactions between hardware and software that a real time operating really can bring a benefit.