DS1077L
TABLE 3
PDN0
PDN1
SHUTDOWN CONTROL
(BIT)
(BIT)
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
Name
Default setting
*
0
PDN1
0
PDN0
0
SEL0
1
EN0
1
0M1
0
0M0
0
LSB
1M1
0
MSB
1M0
0
DIV1
0
-
x
-
x
-
x
-
x
LSB
-
x
-
x
first data byte
*This bit must be set to zero.
second data byte
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
0
0
1
1
0M0
0
1
0
1
PRESCALER
P0 DIVISOR
“M”
1*
2
4
8
1M1
0
0
1
1
1M0
0
1
0
1
PRESCALER
P1 DIVISOR
“M”
1*
2
4
8
*Default Condition
5 of 20
DALLAS [ DALLAS SEMICONDUCTOR ]
