DS1847
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Memory
Location
Name of Location Function of Location
00h to 47h
(Table Select
Byte, E0h, must
be set to 01h or
02h to access the
Look-Up Tables)
User Defined Look-Up Table
(LUT)
This block contains the user defined temperature
settings of the resistors. Values between 00h and
FFh can be written to either table to set the 256
position variable resistors. The first address
location, 00h, is used to set the resistor at -40°C.
Each successive memory location will contain the
resistor setting for the previous temperature +2°C.
For example, memory address 01h is the address
that will set the resistor in a –38°C environment.
For default memory settings and programming
the look-up table, refer to the Programming the
Look-Up Table (LUT) section of the datasheet.
E0h Table Select Byte Writing to this byte determines which of the two
72x8 EEPROM look-up tables is selected for
reading or writing.
01h (Look-Up Table 1 selected)
02h (Look-Up Table 2 selected)
E1h Configuration Byte
TAU – Temperature/Address Update
TEN – Temperature Update Enable
AEN – Address Update Enable
Default setting is 03h, TAU = 1, TEN = 1 and
AEN = 1.
TAU becomes a 1 after a temperature and address
update has occurred as a result of a temperature
conversion. The user can write this bit to 0 and
check for a transition from 0 to 1 in order to
verify that a conversion has occurred.
If TEN = 0, the temperature conversion feature is
disabled. The user sets the resistor in “manual
mode” by writing to addresses F0h and
F1h to control resistors 0 and 1, respectively.
With AEN = 0 the user can operate in a test
mode. Address updates made from the
temperature sensor will cease. The user can load a
memory location into E4h and verify that the
values in locations F0h and F1h are the expected
user-defined values.
TAU TEN AEN
