PreLAB: SysTick

Name:

ID:

I. Introduction

In this tutorial, we will learn how to use SysTick interrupt. We will create functions to count up numbers at a constant rate using SysTick.

The objectives of this tutorial are how to

• Configure SysTick with NVIC

• Create your own functions for the configuration of interrupts

Hardware

• NUCLEO -F411RE

Software

• VS code, CMSIS, EC_HAL

Documentation

• STM32 Reference Manual

II. Basics of SysTick

A. Register List

List of SysTick registers for this tutorial. [Programming Manual ch4.3, ch10.2]

Register List

B. Register Setting

(RCC system clock)

1. PLL, HCLK= 84MHz

(System Tick Configuration)

1. Disable SysTick Timer

SysTick->CTRL ENABLE=0

1. Choose clock signal: System clock or ref. clock(STCLK)

SysTick->CTRL CLKSOURCE = 0 or 1

1. Choose to use Tick Interrupt (timer goes 1->0)

SysTick->CTRL TICKINT = 0 or 1

1. Write reload Counting value (24-bit)

SysTick->LOAD RELOAD = (value-1)

1. Start SysTick Timer

SysTick->CTRL ENABLE=1

1. (option) Read or Clear current counting value

Read from SysTick->VAL

Write clears value

(NVIC Configuration)

1. NVIC SysTick Interrupt priority

2. NVIC SysTick Enable

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III. Tutorial

A. Programming

This is an example code for turning the LED on/off with the button input trigger with a wait function.

Procedure

• Name the project as ‘TU_SysTick’ by creating a new folder as ‘tutorial/TU_SysTick’

• Download the header library files and save under include\.

  • ecSysTick2_student. ecSysTick2_student.c: Click here to download

  • Rename the files as ecSysTick2. ecSysTick2.c

• Download the template code

  • TU_SysTick_student.c : Click here to download

• This is an example code for turning LED on/off with the button input trigger with a wait function.

• Fill in the empty spaces in the code.

• Run the program and check your result.

• Your tutorial report must be submitted to the LMS

• This is a sample program that turns LED on/off at 1 second period using SysTick

Example Code

• Understand the code definition for void SysTick_init() : in ecSysTick2.h

• Read the code definition for void delay_ms( ) in ecSysTick2.h

• You can modify previous LAB code to include delay_ms()

/**
******************************************************************************
* @author  SSSLAB
* @Mod		 2025-9-25 by YKKIM
* @brief   Embedded Controller:  Tutorial ___
*					 - _________________________________
*
******************************************************************************
*/

#include "stm32f411xe.h"
#include "ecRCC2.h"
#include "ecGPIO2.h"
#include "ecSysTick2.h"  // added

volatile uint32_t msTicks = 0;

void setup(void);

void main(void) {	
      // System CLOCK, GPIO Initialiization ----------------------------------------
	setup();

       // While loop ------------------------------------------------------				

	while(1){
                GPIO_write(PB_12, HIGH);        
        	delay_ms (1000);
	        GPIO_write(PB_12, LOW);        
	        delay_ms (1000);        
	}
}




void setup(void)
{
	RCC_PLL_init();              // System Clock = 84MHz	
	//GPIO_init(PA_5, OUTPUT);     // LED for Nucleo
   	GPIO_init(PB_12, OUTPUT);  // LED for Eval Board	JKIT
        SysTick_init(); 
}