STM8S/A Standard Peripherals Firmware Library: Six-step PWM signal generation using TIM1

  ******************** (C)COPYRIGHT 2014 STMicroelectronics *******************
  * @file    TIM1/TIM1_6Steps/readme.txt
  * @author  MCD Application Team
  * @version V2.2.0
  * @date    30-September-2014
  * @brief   Description of the TIM1 6 steps Example.
  ******************************************************************************
  *
  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
  * You may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *        http://www.st.com/software_license_agreement_liberty_v2
  *
  * Unless required by applicable law or agreed to in writing, software 
  * distributed under the License is distributed on an "AS IS" BASIS, 
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  ******************************************************************************
  

Example description

This example shows how to configure the TIM1 peripheral to generate 6 Steps. The TIM1 peripheral offers the possibility to program in advance the configuration for the next TIM1 outputs behaviour (step) and change the configuration of all the channels at the same time. This operation is possible when the COM(commutation) event is used.

The COM event can be generated by software by setting the COM bit in the TIM1_EGR register or by hardware (on TRC rising edge). In this example, a software COM event is generated each 180 ms: using the TIM4 Update interrupt. The TIM1 is configured in Timing Mode, each time a COM event occurs, a new TIM1 configuration will be set in advance.

The following Table describes the TIM1 Channels states:

             | Step1 | Step2 | Step3 | Step4 | Step5 | Step6|

  |Channel1  |   1   |   0   |   0   |   0   |   0   |   1  |

  |Channel1N |   0   |   0   |   1   |   1   |   0   |   0  |

  |Channel2  |   0   |   0   |   0   |   1   |   1   |   0  |

  |Channel2N |   1   |   1   |   0   |   0   |   0   |   0  |

  |Channel3  |   0   |   1   |   1   |   0   |   0   |   0  |

  |Channel3N |   0   |   0   |   0   |   0   |   1   |   1  |

The TIM1 waveform can be displayed using an oscilloscope.

Directory contents

• TIM1\TIM1_6Steps\main.c Main file containing the "main" function
• TIM1\TIM1_6Steps\stm8s_conf.h Library Configuration file
• TIM1\TIM1_6Steps\stm8s_it.c Interrupt routines source
• TIM1\TIM1_6Steps\stm8s_it.h Interrupt routines declaration

Hardware and Software environment

• This example runs on STM8S and STM8A High density, Medium density and Low density devices.

• This example has been tested with STMicroelectronics STM8/128-EVAL evaluation board and can be easily tailored to any other development board.

• Connect TIM1 pins to an oscilloscope as follows:
  • TIM1_CH1 pin (PC.1)
  • TIM1_CH1N pin (PH.7)
  • TIM1_CH2 pin (PC.2)
  • TIM1_CH2N pin (PH.6)
  • TIM1_CH3 pin (PC.3)
  • TIM1_CH3N pin (PH.5)

How to use it ?

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

• Copy all source files from this example folder to the template folder under Project
• Open your preferred toolchain
• Rebuild all files and load your image into target memory
• Run the example
• Connect the TIM1 pins to an oscilloscope

Note:

• High-Density STM8A devices are the STM8AF52xx STM8AF6269/8x/Ax, STM8AF51xx, and STM8AF6169/7x/8x/9x/Ax microcontrollers where the Flash memory density ranges between 32 to 128 Kbytes
• Medium-Density STM8A devices are the STM8AF622x/4x, STM8AF6266/68, STM8AF612x/4x, and STM8AF6166/68 microcontrollers where the Flash memory density ranges between 8 to 32 Kbytes
• High-Density STM8S devices are the STM8S207xx, STM8S007 and STM8S208xx microcontrollers where the Flash memory density ranges between 32 to 128 Kbytes.
• Medium-Density STM8S devices are the STM8S105x and STM8S005 microcontrollers where the Flash memory density ranges between 16 to 32-Kbytes.
• Low-Density STM8S devices are the STM8S103xx, STM8S003 and STM8S903xx microcontrollers where the Flash density is 8 Kbytes.

© COPYRIGHT STMicroelectronics