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Perpetual calendar production based on PCF8563 clock chip

Published time : 2020-03-23 STM32F302R8T6
From this solution you will get more information about Clock chip making,just read it carefully.

Solution Introduction

There are many perpetual calendar clock chips, but compared to DSl302, Philips PCF8563 clock chip and LCM1602 are used for display, which can achieve better results. The circuit diagram is shown in the figure.

Circuit diagram

PCF8563 is a low-power CMOS real-time clock / calendar chip. It provides a programmable clock output, an interrupt output, and a power-down detector. All addresses and data are transferred serially through the I2C bus interface. The maximum bus speed is 400kbit / s. As long as the I2C bus mode is operated during data exchange, the timing requirements are not too high. PCF8563 internal register address and data format description are shown in the attached table.

Unit classification
address
Data Format


Second unit
02H Exact 
BCDdata, 1011001 59 seconds
Minute unit
03H invalid
BCDdata 00-59

Hour unit
04H invalid
BCDdata, 00-23

Day unit
05H invalid
BCDdata, 01-30 BCD data, 01-31, February is 29

Week Unit
06H invalid
0-6
Monthly unit
07H century, invalid BCDdata, 01-12

Annual unit
08H
BCDdata, 00-99

Minute Alarm unit
09H Alarm is active
Alarm value 0-59

Hour Alarm unit 0AH Alarm is active
Alarm value 0-23
Annual  alarm unit 0BH Alarm is active  Alarm value 0-30
Week alarm unit 0CH Alarm is active Alarm value 0-6
CLKOUT 0DH Forbid/valid invalid             frequency 11.1 HZ output
Countdown unit 0EH TE invalid

This circuit uses 89S51 as the main control MCU, PCF8563 generates clock information, and LCM1602 liquid crystal module is used for display. Y1 is a 32.768kHz crystal and Y2 is a 12MHz crystal. BT1 is used as a backup power source to keep the clock data from being lost for 10,000 years; RP1 and RP2 are 9-pin 10kΩ resistors; S1 ~ S4 are used to adjust the time. S2 is used to enter the adjustment mode; and each time you press to change the adjustment item; S1 is used to exit the adjustment state, S3, S4 is used to add 1 minus 1 operation.


Key Components

No. Part Number Manufacturer