• 3 •

Fig 2 Pin Layout

Fig 3 Device diode protection diagram

Table 3 gives the pins’ description.

Table 3: Pin description

Symbol

Pin

Description

OSCI

1

oscillator input

OSCO

2

oscillator output

INT

3

interrupt output (open-drain; active LOW)

4ground

SDA

5

serial Data I/O (open-drain)

SCL

6

serial Clock in

CLKOUT

7

clock output (open-drain)

8

positive power supply

HM8563 contains sixteen 8-bit registers with an auto-increasing address register,an

on-chip 32.768 kHz oscillator with an integrated capacitor, a frequency divider which provides

source clock for the Real-Time Clock (RTC), a programmable clock output, a timer, an alarm, a

The 16 registers are mapped into a memory block, which is addressable, but 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 year counters). Address locations 09H through 0CH contain

alarm registers which define the conditions for an alarm. Address 0DH controls the frequency

of CLKOUT output. 0EH and 0FH are timer control, timer counter register, respectively.

The Seconds, Minutes, Hours, Days, Months, Years as well as the Minute alarm, Hour

alarm and Day alarm registers are all coded in BCD format. The Weekdays and Weekday

alarm register are not 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.

HM8563