Datasheet

Philips Semiconductors
PCF8563
Real time clock/calendar
Product data Rev. 04 — 12 March 2004 4 of 30
9397 750 12999
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
7.2 Pin description
8. Functional description
The PCF8563 contains sixteen 8-bit registers with an auto-incrementing address
register, an on-chip 32.768 kHz oscillator with one integrated capacitor, a frequency
divider which provides the source clock for the Real Time Clock/calender (RTC), a
programmable clock output, a timer, an alarm, a voltage-low detector and a 400 kHz
I
2
C-bus interface.
All 16 registers are designed as addressable 8-bit parallel registers although not all
bits are implemented. The first two registers (memory address 00H and 01H) are
used as control and/or status registers. The memory addresses 02H through 08H are
used as counters for the clock function (seconds up to years counters). Address
locations 09H through 0CH contain alarm registers which define the conditions for an
alarm. Address 0DH controls the CLKOUT output frequency. 0EH and 0FH are the
timer control and timer registers, respectively.
The seconds, minutes, hours, days, weekdays, months, years as well as the minute
alarm, hour alarm, day alarm and weekday alarm registers are all coded in BCD
format.
When one of the RTC registers is read the contents of all counters are frozen.
Therefore, faulty reading of the clock/calendar during a carry condition is prevented.
Fig 5. Device diode protection diagram.
handbook, halfpage
MGR886
SDA
4
5
V
SS
SCL
3
6
INT
CLKOUT
2
7
OSCO
V
DD
1
8
OSCI
PCF8563
Table 3: Pin description
Symbol Pin Description
OSCI 1 oscillator input
OSCO 2 oscillator output
INT 3 interrupt output (open-drain; active LOW)
V
SS
4 ground
SDA 5 serial data input and output
SCL 6 serial clock input
CLKOUT 7 clock output, open-drain
V
DD
8 positive supply voltage