Detailed Description

The MAX6900 contains eight timekeeping registers,

burst address registers, a control register, an on-chip

compatible interface. There are also 31 bytes, 8 bits

wide of SRAM on board. Time and calendar data are

stored in the registers in a binary-coded decimal (BCD)

diagram. Figure 2 shows the MAX6900 functional dia-

gram.

Real-Time Clock

The RTC provides seconds, minutes, hours, day, date,

month, and year information. The end of the month is

automatically adjusted for months with fewer than 31

4

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Typical Operating Characteristics

0

0.3

0.4

0.1

0.2

0.6

0.5

1.0

0.7

0.8

0.9

1.1

1.4

1.5

1.2

1.3

1.6

1.0

2.0 2.5 3.0

1.5

3.5 4.0 4.5

5.5

5.0

6.0

Pin Description

PIN

NAME

FUNCTION

Power Supply

2

X1

32.768kHz External Crystal

3

X2

32.768kHz External Crystal

4

GND

Ground

5

SCL

I

6

SDA

I

Input/Output

—

PAD

Ground

Figure 1. Detailed

PROTOCOL

START

CONDITION

(S)

ACKNOWLEDGE

(A)

STOP

CONDITION

(P)

BIT 7

MSB

(A7)

BIT 0

LSB

(R/W)

BIT 6

(A6)

SCL

SDA