6.5.6. UART Utility Functions

setIntrFlags determines the setting of the interrupt identification register according to which interrupts are currently pending (in intrPending).

genIntr generates an interrupt by marking the corresponding interrupt as pending if the interrupt is enabled and setting the interrupt identification register flags appropriately. In this implementation, no external signal is generated (see Chapter 10 for details of generating an interrupt signal).

clrIntr clears the interrupt pending flag (no need to check if the interrupt is enabled in this case) and sets the appropriate interrupt identification register flags. Again there is no external signal generated in this implementation.

A set of functions are provided to set, clear and test bits in registers. Using these makes the code much more readable^[4].

^[4] Many programmers use #defined macros for functions such as these. However such macros have no encapsulation (they can be used by anyone including the header) and have a nasty habit of clashing with other programs macros. By using functions, the functions can be made private to the UartSC class alone.

A modern C++ compiler will often generate code in line for such small functions, so they will be implemented as efficiently as if they had been #defined as macros. Indeed the added type information gives the potential for greater optimization.