DS1629
DS1629 Thermometer Power-up Modes
Table 5
CNV
0
0
1
1
ISH
0
1
0
1
MODE
Powers up converting continuously (factory default)
Automatically performs one conversion upon power-up. Subsequent conversions
require a Start Convert command.
Powers up in standby; upon Start Convert command, conversions will be performed
continuously.
Powers up in standby; upon Start Convert command, a single conversion will be
performed and stored.
A0, A1
= Alarm Mode. Table 6 defines the DS1629 alarm mode, based on the settings of the A0 and A1
bits. These bits define what event will activate the ALRM output. The alarm flags, CAF, TAF, CAL,
TAL, are functional regardless of the state of these bits. Both locations are read/write and nonvolatile, and
the factory default state disables the ALRM output (A0=A1=0).
Alarm Mode Configuration
Table 6
A1
0
0
1
1
A0
0
1
0
1
ALARM MODE
Neither Thermal or Time (Disabled)
Thermal only
Time only
Either Thermal or Time
OS0, OS1
= Oscillator Output Setting. Table 7 defines the frequency of the OSC output, as defined by
the settings of these bits. Both locations are read/write and nonvolatile, and the factory default state sets
the OSC frequency equal to the crystal frequency (OS0=OS1="1"). The output should be disabled if the
user does not intend to use it to reduce power consumption.
OSC Frequency Configuration
Table 7
OS1
0
0
1
1
OS0
0
1
0
1
OSC FREQUENCY
Disabled
1/8f
0
1/4f
0
f
0
CAF
= Clock Alarm Flag. This volatile status bit will be set to "1" when the clock comparator is in an
active state. Once set, it will remain "1" until reset by writing to or reading from either the clock register
or clock alarm register. A "0" in this location indicates the clock is not in an alarm condition. This is a
read-only bit (writes to this location constitute a "don’ care") and the power-up default is the flag cleared
t
(CAF="0").
TAF
= Thermal Alarm Flag. This volatile status bit will be set to "1" when the thermal comparator is in
an active state. Once set, it will remain "1" until measured temperature falls below the programmed TL
setting. A "0" in this location indicates the thermometer is not in an alarm condition. This is a read-only
bit (writes to this location constitute a “don’ care”) and the power-up default is the flag cleared
t
(TAF="0").
10 of 22
102299
DALLAS [ DALLAS SEMICONDUCTOR ]
