SysTick_CTRL

Bit Field

Read/Write

Field Name

Description

16

R

COUNTFLAG

Reads as 1 if SYSTICK counter has reached 0 since the last time the timer has reached 0. Clears to 0 on read.

2

RW

CLKSOURCE

SYSTICK timer clock source

1

RW

TICKINT

SYSTICK timer interrupt enable

0

RW

ENABLE

SYSTICK timer enable

Bit Field

Field Name

Value Symbol

Value Description

Hex Value

16

COUNTFLAG

SYSTICK_COUNTFLAG_NOT_ZERO

SYSTICK counter has not reached zero since last read

0x0*

SYSTICK_COUNTFLAG_ZERO

SYSTICK counter has reached zero since last read

0x1

2

CLKSOURCE

SYSTICK_CLKSOURCE_EXTREF_CLK

Use external reference clock (STCLK)

0x0*

SYSTICK_CLKSOURCE_CORE_CLK

Use the core clock

0x1

1

TICKINT

SYSTICK_TICKINT_DISABLE

Disable interrupt generation when SYSTICK timer reaches 0

0x0*

SYSTICK_TICKINT_ENABLE

Enable interrupt generation when SYSTICK timer reaches 0

0x1

0

ENABLE

SYSTICK_DISABLE

Disable SYSTICK timer

0x0*

SYSTICK_ENABLE

Enable SYSTICK Timer

0x1