Datasheet

DocID024647 Rev 1 69/138
RM0352 System timer (SysTick)
137
Type: R/W
Reset:
Description: SysTick reload value register
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.
9.3.3 SysTick current value register (SYST_CVR)
Address: SysTick BaseAddress + 0x008
Type: R/W
Reset:
Description: SysTick current value register
9.3.4 SysTick calibration value register (SYST_CALIB)
Address: SysTick BaseAddress + 0x00C
Type: R/O
[31:24] RESERVED
[23:0] RELOAD: value to load into the SYST_CVR when the counter is enabled and
when reaches zero.
The RELOAD value can be any value in the range 0x00000001-0x00FFFFFF.
Programming 0x00000000 has no effect because the SysTick exception
request and COUNTFLAG are activated when counting down from 1 to 0.
Table 68. SysTick current value register
SysTick current value register (SYST_CVR)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
RESERVED CURRENT
[31:24] RESERVED
[23:0] CURRENT: read returns the current value of the SysTick counter.
A write of any value clears the field to zero and clears the
SYST_CSR.COUNTFLAG bit to zero.
Table 69. SysTick calibration value register
SysTick calibration value register (SYST_CALIB)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 109876543210
NOREF SKEW RESERVED TENMS