To configure the clock module statically, the SYS/BIOS configuration tool XGCONF can be used and select the clock module. As can be seen on this slide the tick source is selectable and can be configured to use the timer input or an external system input to act as the clock heartbeat. It is also possible to select a source of NULL, but that is an optimization that will prevent any clock function from firing and will prevent any SYS/BIOS API calls to have a timeout; for example, a Semaphore_pend() call cannot have a timeout value in that case. The timer ID is used to specify which of the chip’s physical timers are actually utilized. A value of -1 will allow the config tool to select a default timer. The clock module is implemented as a software interrupt that is posted by the underlying timer module, so the priority of that Swi is settable. Finally the tickperiod specifies the period between the system ticks.