DS1077L

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TABLE 3

PDN0

(BIT)

PDN1

(BIT)

SHUTDOWN CONTROL

0

0

None*

0

1

CTRL1

1

0

CTRL0

1

1

CTRL0 or CTRL1

*CTRL0 performs a power-down if SEL0 and EN0 are both 0. (See Table 1.)

Serial Data Input/Output (SDA) – Input/output pin for the 2-wire serial interface used for data transfer.

Serial Clock Input (SCL) – Input pin for the 2-wire serial interface used to synchronize data movement

on the serial interface.

REGISTER FUNCTIONS

The user-programmable registers can be programmed by the user to determine the mode of operation

(MUX), operating frequency (DIV) and bus settings (BUS). Details of how these registers are

programmed can be found in a later section; in this section the functions of the registers are described.

The register setting are nonvolatile, the values are stored automatically or as required in EEPROM when

the registers are programmed via the SDA and SCL pins.

MUX WORD

MSB

LSB

MSB

LSB

Name

*

PDN1

PDN0

SEL0

EN0

0M1

0M0

1M1

1M0

DIV1

-

-

-

-

-

-

Default setting

0

0

0

1

1

0

0

0

0

0

x

x

x

x

x

x

first data byte

second data byte

*This bit must be set to zero.

DIV1 (bit)

This bit allows the output of the prescaler P1 to be routed directly to the OUT1 pin (DIV1 = 1). The N

divider is bypassed so the programmed value of N is ignored. If DIV1 = 0 (default) the N divider

functions normally.

0M1, 0M0, 1M1, 1M0 (bits)

These bits set the prescalers P0 and P1, to divide by 1, 2, 4, or 8. (See Table 4.)

TABLE 4

0M1

0M0

PRESCALER

P0 DIVISOR

“M”

1M1

1M0

PRESCALER

P1 DIVISOR

“M”

0

0

1*

0

0

1*

0

1

2

0

1

2

1

0

4

1

0

4

1

1

8

1

1

8

*Default Condition