Piggybacking on the SysTick Interrupt

If you need to check certain things periodically, and if the SysTick interrupt of every 10ms is of a sufficient frequency for this use, then you can piggyback your checking onto the REXIS SysTick interrupt handler without using another interrupt source. Just beware that the code should run as fast as possible so as not to impact REXIS and the system’s performance. To do this, define the function rexis_UserSysTick_Handler as described below.