1 FEATURES
· I2C-bus interface operating supply voltage: 2.5 V to 6 V
· Clock operating supply voltage (0 to +70 °C):
1.0 V to 6.0 V
· 240 ´ 8-bit low-voltage RAM
· Data retention voltage: 1.0 V to 6 V
· Operating current (at fSCL = 0 Hz): max. 50 mA
· Clock function with four year calendar
· Universal timer with alarm and overflow indication
· 24 or 12 hour format
· 32.768 kHz or 50 Hz time base
· Serial input/output bus (I2C)
· Automatic word address incrementing
· Programmable alarm, timer and interrupt function
· Slave address:
– READ: A1 or A3
– WRITE: A0 or A2.

2 GENERAL DESCRIPTION
The PCF8583 is a clock/calendar circuit based on a
2048-bit static CMOS RAM organized as 256 words by
8 bits. Addresses and data are transferred serially via the
two-line bidirectional I2C-bus. The built-in word address
register is incremented automatically after each written or
read data byte. Address pin A0 is used for programming
the hardware address, allowing the connection of two
devices to the bus without additional hardware.
The built-in 32.768 kHz oscillator circuit and the first
8 bytes of the RAM are used for the clock/calendar and
counter functions. The next 8 bytes may be programmed
as alarm registers or used as free RAM space.
The remaining 240 bytes are free RAM locations.