Obsolete

Product(s)

- Obsolete

Product(s)

Obsolete

Product(s)

- Obsolete

Product(s)

M48T59, M48T59Y, M48T59V

Clock operations

15/32

Figure 8.

Crystal accuracy across temperature

Figure 9.

Clock calibration

3.5

Setting the alarm clock

Registers 1FF5h-1FF2h contain the alarm settings. The alarm can be configured to go off at

a prescribed time on a specific day of the month or repeat every month, day, hour, minute, or

second. It can also be programmed to go off while the M48T59/Y/V is in the battery back-up

mode of operation to serve as a system wake-up call.

Bits RPT1-RPT4 put the alarm in the repeat mode of operation. Table 6 on page 16 shows

the possible configurations. Codes not listed in the table default to the once per second

mode to quickly alert the user of an incorrect alarm setting.

Note:

User must transition address (or toggle chip enable) to see Flag Bit change.

When the clock information matches the alarm clock settings based on the match criteria

defined by RPT1-RPT4, AF (Alarm Flag) is set. If AFE (Alarm Flag Enable) is also set, the

AI00999

–160

0

10203040506070

Frequency (ppm)

Temperature

°C

80

–10

–20

–30

–40

–100

–120

–140

–40

–60

–80

20

0

–20

= -0.038

(T - T

F

ppm

C

2

T

AI00594B

NORMAL

POSITIVE

CALIBRATION

NEGATIVE

CALIBRATION