Atmel SAM4S Xplained Pro Starter Kit Atmel ATSAM4S-XSTK ATSAM4S-XSTK データシート
製品コード
ATSAM4S-XSTK
211
SAM4S [DATASHEET]
11100E–ATARM–24-Jul-13
12.10.1.2SysTick Reload Value Registers
Name:
SYST_RVR
Access: Read-write
Reset: 0x000000000
The SYST_RVR register specifies the start value to load into the SYST_CVR register.
• RELOAD
Value to load into the SYST_CVR register when the counter is enabled and when it reaches 0.
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.
because the SysTick exception request and COUNTFLAG are activated when counting from 1 to 0.
The RELOAD value is calculated according to its use: For example, to generate a multi-shot timer with a period of N processor
clock cycles, use a RELOAD value of N-1. If the SysTick interrupt is required every 100 clock pulses, set RELOAD to 99.
clock cycles, use a RELOAD value of N-1. 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
RELOAD
15
14
13
12
11
10
9
8
RELOAD
7
6
5
4
3
2
1
0
RELOAD