本应用笔记的目的是协助用户在应用中实现实时时钟的的设计。 UM10301 User Manual for NXP Real Time Clocks PCF85x3, PCA8565 and PCF2123, PCA2125 Rev. 01 ― 23 December 2008 User manual Document information Info Content Keywords PCF8563, PCF8573, PCF8583, PCF8593, PCA8565, PCF2123, PCA2125, PCF2120, RTC, real time clock, timekeeping, crystal, 32.768 kHz, backup. Abstract This application note aims to assist a user of above mentioned Real Time Clocks in achieving succesful design-in and application. It contains useful hints with respect to electrical schematic and PCB layout as well as code examples for the well established NXP……