DS1689/DS1693

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minute with “don’t care” codes in the hours and minute alarm bytes. The “don’t care” codes in all three

alarm bytes create an interrupt every second. The three alarm bytes may be used in conjunction with the

date alarm as described in the Wakeup/Kickstart section. The century counter will be discussed later in

this text.

Table 1. Time, Calendar, and Alarm Data Modes

RANGE

ADDRESS

LOCATION

FUNCTION

DECIMAL

RANGE

BINARY DATA

MODE

BCD DATA

MODE

00H

Seconds

0-59

00-3B

00-59

01H

Seconds Alarm

0-59

00-3B

00-59

02H

Minutes

0-59

00-3B

00-59

03H

Minutes Alarm

0-59

00-3B

00-59

Hours 12-hr Mode

1-12

01-0C AM, 81-8C PM

01-12 AM, 81-92 PM

04H

Hours 24-hr Mode

0-23

00-17

00-23

Hours Alarm 12-hr

Mode

1-12

01-0C AM, 81-8C PM

01-12 AM, 81-92 PM

05H

Hours Alarm 24-hr

Mode

0-23

00-17

00-23

06H

Day of Week

Sunday=1

1-7

01-07

01-07

07H

Date of Month

1-31

01-1F

01-31

08H

Month

1-12

01-0C

01-12

09H

Year

0-99

00-63

00-99

BANK1, 48H

Century

0-99

00-63

00-99

BANK 1, 49H

Date Alarm

1-31

01-1F

01-31

CONTROL REGISTERS

The four control registers; A, B, C, and D reside in both bank 0 and bank 1. These registers are accessible

at all times, even during the update cycle.

NONVOLATILE RAM—RTC

The 114 general-purpose nonvolatile RAM bytes are not dedicated to any special function within the

DS1689/DS1693. They can be used by the application program as nonvolatile memory and are fully

available during the update cycle. This memory is directly accessible when bank 0 is selected.

INTERRUPT CONTROL

The DS1689/DS1693 include six separate, fully automatic sources of interrupt for a processor:

1. Alarm interrupt

2. Periodic interrupt

3. Update-ended interrupt

4. Wake-up interrupt

5. Kickstart interrupt

6. RAM clear interrupt

The conditions, which generate each of these independent interrupt conditions, are described in greater

detail elsewhere in this data sheet. This section describes the overall control of the interrupts.