Datasheet

DS1922L/DS1922T
Temperature Logger iButton with 8KB
Data-Log Memory
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Mission Example: Prepare
and Start a New Mission
Assumption: The previous mission has been ended by
using the Stop Mission command. Passwords are not
enabled. The device is a DS1922L.
Starting a mission requires three steps:
Step 1: Clear the data of the previous mission.
Step 2: Write the setup data to register page 1.
Step 3: Start the new mission.
Step 1: Clear the data of the previous mission.
With only a single device connected to the bus master,
the communication of step 1 looks like this:
RST
Forced Conversion
PD FCSelect FF LoopFFh
To read the result and to verify success, read the addresses 020Ch to 020Fh (results) and the Device Samples
Counter at address 0223h to 0225h. If the count has incremented, the command was executed successfully.
FF LoopRST
Start Mission with Password
PD SMSelect <PW/Dummy> FFh
To verify success, read the General Status register at address 0215h. If MIP is 1 and MEMCLR is 0, the command
was executed successfully.
RST
Stop Mission with Password
PD STPSelect FF Loop<PW/Dummy> FFh
To verify success, read the General Status register at address 0215h. If MIP is 0, the command was executed
successfully.
1-Wire Communication Examples (continued)
MASTER MODE DATA (LSB FIRST) COMMENTS
Tx (Reset) Reset pulse
Rx (Presence) Presence pulse
Tx CCh Issue “Skip ROM” command
Tx 96h Issue “Clear Memory” command
Tx <8 FFh bytes> Send dummy password
Tx FFh Send dummy byte
Tx (Reset) Reset pulse
Rx (Presence) Presence pulse