System Timer (Systick); Configuration - STMicroelectronics STM32 Cortex-M3 Manual

4.7 System Timer (SysTick)

2 Electrocardiogram (Ecg) Signals
sets up a system timer routine and shows a running light on GPIOB. The system
sysTick
timer is a periodical timer that can be set up easily with the configuration wizard
(see Figure 4.8).
The Cortex core includes a 24-bit down counter, with auto reload and end of count interrupt. This
The Electrocardiogram (Ecg)
is intended to provide a standard timer for all Cortex-based microcontrollers. The SysTick timer
is intended to be used to provide a system tick for an RTOS, or to generate a periodic interrupt for
• Ecg: electrical manifestation of heart activity recorded
scheduled tasks. The SysTick Control and status register in the Cortex-M3 System control space
from the body surface
unit allows you to select the SysTick clock source. By setting the CLKSOURCE bit the SysTick
timer will run at the CPU frequency. When cleared the timer will run at 1/8 CPU frequency.
• monitoring of heart rate
4.7.1 Configuration
The Ecg signal can be recorded fairly easily with surface
Enable the System Timer Configuration in the configuration wizard and select a clock source. Choose
electrodes placed on the limbs and/or the chest, see pages
the time interval and enable the interrupt. The function
below.
the -routine gets called when the sysTick interrupt occurs.
main()
Josef Goette
32
2
Figure 4.8: System Timer Configuration Wizard
1 Intro
6–16
void SysTick Handler (void)
2009
STM32 Cortex-M3 Tutorial
4 Peripherals
above