Philips Semiconductors

PCA8565

Real time clock/calender

Product data

Rev. 01 — 31 March 2003

9 of 26

9397 750 10695

© Koninklijke Philips Electronics N.V. 2003. All rights reserved.

8.6.5

CLOCKOUT control register

8.6.6

Countdown timer

The timer register is an 8-bit binary countdown timer. It is enabled and disabled via

the timer control register bit TE. The source clock for the timer is also selected by the

timer control register. Other timer properties such as interrupt generation are

controlled via control/status 2 register.

Table 18:

Minute alarm (address 09H) bits description

Bit

Symbol

Value

Description

7

AE

0

minute alarm is enabled

1

minute alarm is disabled

6 to 0

alarm minutes

00 to 59

this register holds the minute alarm information coded in BCD format

Table 19:

Hour alarm (address 0AH) bits description

Bit

Symbol

Value

Description

7

AE

0

hour alarm is enabled

1

hour alarm is disabled

5 to 0

alarm hours

00 to 23

this register holds the hour alarm information coded in BCD format

Table 20:

Day alarm (address 0BH) bits description

Bit

Symbol

Value

Description

7

AE

0

day alarm is enabled

1

day alarm is disabled

5 to 0

alarm days

01 to 31

this register holds the day alarm information coded in BCD format

Table 21:

Weekday alarm (address 0CH) bits description

Bit

Symbol

Value

Description

7

AE

0

weekday alarm is enabled

1

weekday alarm is disabled

2 to 0

alarm

weekdays

0 to 6

this register holds the weekday alarm information coded in BCD format

Table 22:

CLKOUT control (address 0DH) bits description

Bit

Symbol

Value

Description

7

FE

0

the CLKOUT output is inhibited and CLKOUT output is set to high-impedance

1

the CLKOUT output is activated

1 to 0

FD1 and

FD0

these bits control the frequency output at pin CLKOUT, see Table 23

Table 23:

FD1 and FD0: CLKOUT frequency selection

FD1

FD0

CLKOUT frequency

0

0

32.768 kHz

0

1

1024 Hz

1032 Hz

111 Hz