TIM_PWM_Output

  ******************** (C) COPYRIGHT 2010 STMicroelectronics *******************
  * @file    TIM/PWM_Output/readme.txt 
  * @author  MCD Application Team
  * @version V3.4.0
  * @date    10/15/2010
  * @brief   Description of the TIM PWM_Output example.
  ******************************************************************************
  * THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
  * WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
  * TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
  * DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
  * FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
  * CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
  ******************************************************************************
   
Example Description

This example shows how to configure the TIM peripheral in PWM (Pulse Width Modulation) mode.

The TIM3CLK frequency is set to SystemCoreClock / 2 (Hz), to get TIM3 counter clock at 24 MHz the Prescaler is computed as following:

The TIM3 is running at 36 KHz: TIM3 Frequency = TIM3 counter clock/(ARR + 1) = 24 MHz / 666 = 36 KHz The TIM3 CCR1 register value is equal to 500, so the TIM3 Channel 1 generates a PWM signal with a frequency equal to 36 KHz and a duty cycle equal to 50%: TIM3 Channel1 duty cycle = (TIM3_CCR1/ TIM3_ARR + 1)* 100 = 50%

The TIM3 CCR2 register value is equal to 375, so the TIM3 Channel 2 generates a PWM signal with a frequency equal to 36 KHz and a duty cycle equal to 37.5%: TIM3 Channel2 duty cycle = (TIM3_CCR2/ TIM3_ARR + 1)* 100 = 37.5%

The TIM3 CCR3 register value is equal to 250, so the TIM3 Channel 3 generates a PWM signal with a frequency equal to 36 KHz and a duty cycle equal to 25%: TIM3 Channel3 duty cycle = (TIM3_CCR3/ TIM3_ARR + 1)* 100 = 25%

The TIM3 CCR4 register value is equal to 125, so the TIM3 Channel 4 generates a PWM signal with a frequency equal to 36 KHz and a duty cycle equal to 12.5%: TIM3 Channel4 duty cycle = (TIM3_CCR4/ TIM3_ARR + 1)* 100 = 12.5%

The PWM waveform can be displayed using an oscilloscope.

Directory contents
Hardware and Software environment
How to use it ?

In order to make the program work, you must do the following:

Tip: You can tailor the provided project template to run this example, for more details please refer to "stm32f10x_stdperiph_lib_um.chm" user manual; select "Peripheral Examples" then follow the instructions provided in "How to proceed" section.

Note:
  • Low-density Value line devices are STM32F100xx microcontrollers where the Flash memory density ranges between 16 and 32 Kbytes.
  • Low-density devices are STM32F101xx, STM32F102xx and STM32F103xx microcontrollers where the Flash memory density ranges between 16 and 32 Kbytes.
  • Medium-density Value line devices are STM32F100xx microcontrollers where the Flash memory density ranges between 64 and 128 Kbytes.
  • Medium-density devices are STM32F101xx, STM32F102xx and STM32F103xx microcontrollers where the Flash memory density ranges between 64 and 128 Kbytes.
  • High-density Value line devices are STM32F100xx microcontrollers where the Flash memory density ranges between 256 and 512 Kbytes.
  • High-density devices are STM32F101xx and STM32F103xx microcontrollers where the Flash memory density ranges between 256 and 512 Kbytes.
  • XL-density devices are STM32F101xx and STM32F103xx microcontrollers where the Flash memory density ranges between 512 and 1024 Kbytes.
  • Connectivity line devices are STM32F105xx and STM32F107xx microcontrollers.

© COPYRIGHT 2010 STMicroelectronics

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