DS2422 Maxim, DS2422 Datasheet - Page 23

• Manufacturer Part Number: DS2422
• Description: The DS2422 temperature/data logger combines the core functions of a fully featured data logger in a single chip
• Manufacturer: Maxim

lower address. Knowing the starting time point (Mission Time Stamp) and the interval between temperature
measurements one can reconstruct the time and date of each measurement.
There are two alternatives to the way the DS2422 behaves after the datalog memory is filled with data. The user
can program the device to either stop any further recording (disable “rollover”) or overwrite the previously recorded
data (enable “rollover”), one entry at a time, starting again at the beginning of the respective memory section. The
contents of the Mission Samples Counter in conjunction with the sample rate and the Mission Time Stamp will then
allow reconstructing the time points of all values stored in the datalog memory. This gives the exact history over
time for the most recent measurements taken. Earlier measurements cannot be reconstructed.
Figure 10A. One-Channel Logging
Figure 10B. Two-Channel Logging, Equal Resolution
ETL = 1; EDL = 0 or
TLFS = DLFS = 0
External Data
Temperature
TLFS = DLFS = 0
ETL = 0; EDL = 1
8-bit entries
8-bit entries
External data
Temperature
ETL = EDL = 1
8-bit entries
4096
4096
8192
or
1000h
1FFFh
2000h
2FFFh
1000h
2FFFh
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ETL = 1; EDL = 0 or
TLFS = DLFS = 1
External Data
16-bit entries
16-bit entries
Temperature
TLFS = DLFS = 1
ETL = 0; EDL = 1
External data
16-bit entries
Temperature
ETL = EDL = 1
2048
2048
4096
or
1000h
1FFFh
2000h
2FFFh
1000h
2FFFh
With 16-bit format,
the most-significant
byte is stored at the
lower address.
With 16-bit format,
the most-significant
byte is stored at the
lower address.