Basic CMSIS Example

A typical example for using the CMSIS layer is provided below. The example is based on a STM32F10x Device.

#include <stm32f10x.h>                           // File name depends on device used
 
uint32_t volatile msTicks;                       // Counter for millisecond Interval
 
void SysTick_Handler (void) {                    // SysTick Interrupt Handler
  msTicks++;                                     // Increment Counter
}
 
void WaitForTick (void)  {
  uint32_t curTicks;
 
  curTicks = msTicks;                            // Save Current SysTick Value
  while (msTicks == curTicks)  {                 // Wait for next SysTick Interrupt
    __WFE ();                                    // Power-Down until next Event/Interrupt
  }
}
 
void TIM1_UP_IRQHandler (void) {                 // Timer Interrupt Handler
  ;                                              // Add user code here
}
 
void timer1_init(int frequency) {                // Set up Timer (device specific)
  NVIC_SetPriority (TIM1_UP_IRQn, 1);            // Set Timer priority
  NVIC_EnableIRQ (TIM1_UP_IRQn);                 // Enable Timer Interrupt
}
 
 
void Device_Initialization (void)  {             // Configure & Initialize MCU
  if (SysTick_Config (SystemCoreClock / 1000)) { // SysTick 1mSec
       : // Handle Error 
  }
  timer1_init ();                                // setup device-specific timer
}
 
 
// The processor clock is initialized by CMSIS startup + system file
void main (void) {                                   // user application starts here
  Device_Initialization ();                      // Configure & Initialize MCU
  while (1)  {                                   // Endless Loop (the Super-Loop)
    __disable_irq ();                            // Disable all interrupts
    Get_InputValues ();                          // Read Values
    __enable_irq ();                             // Enable all interrupts 
    Calculation_Response ();                     // Calculate Results
    Output_Response ();                          // Output Results
    WaitForTick ();                              // Synchronize to SysTick Timer
  }
}