/******************** (C) COPYRIGHT 2008 STMicroelectronics ******************** * File Name : readme.txt * Author : MCD Application Team * Version : V2.0.1 * Date : 06/13/2008 * Description : Description of the TIM 7PWM_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 TIM1 peripheral to generate 7 PWM signals with 4 different duty cycles. TIM1CLK is fixed to 72 MHz, the TIM1 Prescaler is equal to 0 so the TIM1 counter clock used is 72 MHz. TIM1 frequency is defined as follow: TIM1 frequency = TIM1CLK/(TIM1_Period + 1) = 17.57 KHz. The TIM1 CCR1 register value is equal to 0x7FF, so the TIM1 Channel 1 and TIM1 Channel 1N generate a PWM signal with a frequency equal to 17.57 KHz and a duty cycle equal to: TIM1 Channel1 duty cycle = TIM1_CCR1 /( TIM1_Period + 1) = 50%. The TIM1 CCR2 register value is equal to 0x5FF, so the TIM1 Channel 2 and TIM1 Channel 2N generate a PWM signal with a frequency equal to 17.57 KHz and a duty cycle equal to: TIM1 Channel2 duty cycle = TIM1_CCR2 / ( TIM1_Period + 1)= 37.5%. The TIM1 CCR3 register value is equal to 0x3FF, so the TIM1 Channel 3 and TIM1 Channel 3N generate a PWM signal with a frequency equal to 17.57 KHz and a duty cycle equal to: TIM1 Channel3 duty cycle = TIM1_CCR3 / ( TIM1_Period + 1) = 25%. The TIM1 CCR4 register value is equal to 0x1FF, so the TIM1 Channel 4 generate a PWM signal with a frequency equal to 17.57 KHz and a duty cycle equal to: TIM1 Channel4 duty cycle = TIM1_CCR4 / ( TIM1_Period + 1) = 12.5%. The TIM1 waveform can be displayed using an oscilloscope. Directory contents ================== stm32f10x_conf.h Library Configuration file stm32f10x_it.c Interrupt handlers stm32f10x_it.h Interrupt handlers header file main.c Main program Hardware environment ==================== This example runs on STMicroelectronics STM3210B-EVAL and STM3210E-EVAL evaluation boards and can be easily tailored to any other hardware. Connect the TIM1 pins to an oscilloscope to monitor the different waveforms: - TIM1_CH1 pin (PA.08) - TIM1_CH1N pin (PB.13) - TIM1_CH2 pin (PA.09) - TIM1_CH2N pin (PB.14) - TIM1_CH3 pin (PA.10) - TIM1_CH3N pin (PB.15) - TIM1_CH4 pin (PA.11) How to use it ============= In order to make the program work, you must do the following: - Create a project and setup all your toolchain's start-up files - Compile the directory content files and required Library files: + stm32f10x_lib.c + stm32f10x_tim.c + stm32f10x_gpio.c + stm32f10x_rcc.c + stm32f10x_nvic.c + stm32f10x_flash.c - Link all compiled files and load your image into target memory - Run the example ******************* (C) COPYRIGHT 2008 STMicroelectronics *****END OF FILE******