AN14278 - PSoC® 1: Measurement and Compensation of the Internal Low Speed Oscillator

AN14278 outlines the use of the PSoC® 1 internal main oscillator (IMO) to measure and compensate for wider tolerance on the internal low speed oscillator (ILO). This application note describes how to use the main oscillator to measure the frequency of the low speed oscillator to compensate for the ILO inaccuracy. This provides greater accuracy for sleep duration and other low power clocking needs.

Introduction

The PSoC Internal Low Speed Oscillator (ILO) is a 32 kHz internal oscillator that is physically separate from the Internal Main Oscillator (IMO). The ILO is used for the sleep timer, watchdog timer, and also as a clock input for digital blocks. Unlike the IMO, the ILO continues operating even when the PSoC is in its low power sleep mode.