
DS1922E
iButton High-Temperature Logger with
8KB Data-Log Memory
1-Wire Communication Examples (continued)
Forced Conversion
RST PD Select FC
FFh
FF Loop
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.
Start Mission with Password
RST PD Select SM
<PW/Dummy>
FFh
FF Loop
To verify success, read the General Status register at address 0215h. If MIP is 1 and MEMCLR is 0, the command
was executed successfully.
Stop Mission with Password
RST PD Select STP
<PW/Dummy>
FFh
FF Loop
To verify success, read the General Status register at address 0215h. If MIP is 0, the command was executed
successfully.
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.
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:
40
MASTER MODE
Tx
Rx
Tx
Tx
Tx
Tx
Tx
Rx
DATA (LSB FIRST)
(Reset)
(Presence)
CCh
96h
<8 FFh bytes>
FFh
(Reset)
(Presence)
COMMENTS
Reset pulse
Presence pulse
Issue “Skip ROM ” command
Issue “Clear Memory” command
Send dummy password
Send dummy byte
Reset pulse
Presence pulse
Maxim Integrated