RTC_LSI_Calib

  ******************** (C) COPYRIGHT 2010 STMicroelectronics *******************
  * @file    RTC/LSI_Calib/readme.txt 
  * @author  MCD Application Team
  * @version V3.4.0
  * @date    10/15/2010
  * @brief   Description of the RTC LSI_Calib 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 demonstrates and explains how to use the LSI clock source auto calibration to get a precise RTC clock. As an application example, it demonstrates how to configure the TIM5 timer internally connected to LSI clock output, in order to adjust the RTC prescaler.

The Low Speed External (LSI) clock is used as RTC clock source. After reset, the RTC prescaler is set with the default value (40000). The inaccuracy of the LSI clock causes the RTC Second signal to be inaccurate. This signal is output on the Tamper pin (PC.13) and can be measured by on oscilloscope or a frequencymeter.

The program waits until Key Push button is pressed to begin the auto calibration procedure:

The RTC Second signal can be monitored either on Tamper pin or on LED1 which is toggled into the RTC Second interrupt service routine.

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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