TICKINT=value1, CLKSOURCE=value1, ENABLE=value1
SysTick Control and Status Register
| ENABLE | Counter Enable 0 (value1): Counter disabled. 1 (value2): Counter enabled. |
| TICKINT | SysTick Exception Request 0 (value1): Counting down to zero does not assert the SysTick exception request. 1 (value2): Counting down to zero to assert the SysTick exception request. |
| CLKSOURCE | Clock Source 0 (value1): External clock. 1 (value2): Processor clock. |
| COUNTFLAG | Counter Flag |