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 document details how to use the LIN bus standard's sync field to synchronize and calibrate the variable internal RC oscillator of STM8A/S microcontrollers. This technique allows slave nodes to save costs by avoiding external crystal or resonator oscillators, as they can derive their system clock from the calibrated HSI.
The nominal frequency (fys) of the HSI oscillator is 16 MHz.
The device is calibrated at an ambient temperature of 25 °C and a supply voltage of 5 V.
The accuracy for the overall temperature and voltage range is +5 %.