ST STM32F0 Series User Manual

PM0215 Core peripherals
Doc ID 022979 Rev 1 87/91
4.4.2 SysTick reload value register (STK_RVR)
Address offset: 0x04
Reset value: Unknown
The STK_RVR specifies the start value to load into the STK_CVR.
4.4.3 SysTick current value register (STK_CVR)
Address offset: 0x08
Reset value: Unknown
The STK_CVR contains the current value of the SysTick counter.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
Reserved
RELOAD[23:16]
rw rw rw rw rw rw rw rw
1514131211109876543210
RELOAD[15:0]
rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw
Bits 31:24 Reserved, must be kept cleared.
Bits 23:0 RELOAD: RELOAD value
Value to load into the STK_CVR when the counter is enabled and when it reaches 0.
Calculating the RELOAD value
The RELOAD value can be any value in the range 0x00000001-0x00FFFFFF. A start value of
0 is possible, but has no effect because the SysTick exception request and COUNTFLAG are
activated when counting from 1 to 0. To generate a multi-shot timer with a period of N
processor clock cycles, use a RELOAD value of N-1. For example, if the SysTick interrupt is
required every 100 clock pulses, set RELOAD to 99.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
Reserved
CURRENT[23:16]
rw rw rw rw rw rw rw rw
1514131211109876543210
CURRENT[15:0]
rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw
Bits 31:24 Reserved, must be kept cleared.
Bits 23:0 CURRENT: Current counter value
Reads return the current value of the SysTick counter.
A write of any value clears the field to 0, and also clears the COUNTFLAG bit in the
STK_CSR register to 0.

ST STM32F0 Series Specifications

General

Brand	ST
Model	STM32F0 Series
Category	Microcontrollers
Language	English