PCF8563 is an industrial-grade multi-function clock/calendar chip with extremely low power consumption with I2C bus interface function introduced by PHILIPS. PCF8563's various alarm functions, timer functions, clock output functions and interrupt output functions can complete various complex timing services, and even provide watchdog functions for single-chip microcomputers. It is a cost-effective clock chip, which has been widely used in electric meters, water meters, gas meters, telephones, fax machines, portable instruments and battery-powered instruments and other products.

Basic Information

Table of contents

1 chip introduction

2 system applications

3-pin description

4 How it works

5 Application Overview

6 Program Examples

Introduction of Folding Chip

Peripheral device PCF8563I2C real-time clock/calendar chip

Folding system application

This paper introduces the structure, function and working principle of PCF8563. Combined with its application example in 8051 system, the hardware interface circuit and C language software programming program of PCF8563 and 8051 single-chip microcomputer are given.

I2C bus serial interface PCF8563BCD code C language

Introduction to PCF8563

PCF8563 is a low-power CMOS real-time clock/calendar chip produced by PHILIPS. The maximum bus speed of the chip is 400kbits/s. After each read and write data, the embedded word address register will automatically generate increments. PCF8563 can be widely used in mobile phones, portable instruments, fax machines, battery power and other products.

PCF8563 has 16 8-bit registers, including: address register with auto-increment, built-in 32.768kHz oscillator (with an internal integrated capacitor), frequency divider (used to provide source clock for real-time clock RTC), optional Program clock output, timer, alarm, brownout detector and 400kHz I2C bus interface. All 16 registers are designed as addressable 8-bit parallel registers, but not all bits are useful. When an RTC register is read, the contents of all counters are latched, so that misreading of the clock/calendar chip can be inhibited under transfer conditions. Table 2 and Table 3 list the overview of each register and the corresponding memory addresses and functions, and also list their BCD format codes. In the table -- means invalid bit, 0 means this bit should be set to logic. The century digit C=0 in Table 3 specifies the century number as 20XX, and C=1 specifies the century number as 19XX. The century bit only changes when 99 in the year register changes to 00.

Its main features are:

1. Wide voltage range 1.0~5.5V, reset voltage standard value Vlow=0.9V.

2. Ultra-low power consumption: the typical value is 0.25uA (VDD=3.0V, Tamb=25℃).

3. Programmable clock output frequency: 32.768KHz, 1024Hz, 32Hz, 1Hz.

4. Four alarm functions and timer functions.

5. Contains reset circuit, oscillator capacitor and power-down detection circuit.

6. Open-drain interrupt output.

7. 400kHz I2C bus (VDD=1.8~5.5V), read 0A3H from address; write 0A2H.