AN3258 Datasheet, PDF (1/16 Pages) STMicroelectronics – Local interconnect network

AN3258
Application note
STM8A/S HSI oscillator calibration
using LIN automatic resynchronization
Introduction
Local interconnect network (LIN) is a widely used standard for communication between
various nodes present inside the electronic control unit (ECU) of a vehicle. LIN sync frame,
which is defined by LIN standard, is used as a reference by the LIN slave nodes for clock
synchronization. Using this technique, LIN slave nodes can calibrate the variable internal
RC oscillator and use it as the system clock source. Therefore, the LIN slave node
application can save the cost of using crystal or resonator oscillators.
This application note describes a method to calibrate the STM8A/S high-speed internal
(HSI) oscillator using the LIN automatic resynchronization feature of the LINUART/UART1
peripheral. The calibration method is also provided with a software routine. It can be
downloaded from www.st.com.
The user must be familiar with the LIN bus standard, STM8A/S microcontroller architecture,
and the basics of C language. Detailed information about the STM8A/S microcontroller
peripheral features, hardware registers, and electrical characteristics are available in the
STM8A (RM0009) and STM8S (RM0016) reference manuals and the product datasheets.
October 2010
Doc ID 17825 Rev 1
1/16
www.st.com