Datasheet

DS1922L/DS1922T
Temperature Logger iButton with 8KB
Data-Log Memory
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With only a single device connected to the bus master,
the communication of step 2 looks like this:
MASTER MODE DATA (LSB FIRST) COMMENTS
Tx (Reset) Reset pulse
Rx (Presence) Presence pulse
Tx CCh Issue “Skip ROM” command
Tx 0Fh Issue “Write Scratchpad” command
Tx 00h TA1, beginning offset = 00h
Tx 02h TA2, address = 0200h
Tx <25 Data Bytes> Write 25 bytes of data to scratchpad
Tx <7 FFh Bytes> Write through the end of the scratchpad
Tx (Reset) Reset pulse
Rx (Presence) Presence pulse
Tx CCh Issue “Skip ROM” command
Tx AAh Issue “Read Scratchpad” command
Rx 00h Read TA1, beginning offset = 00h
Rx 02h Read TA2, address = 0200h
Rx 1Fh Read E/S, ending offset = 1Fh, flags = 0h
Rx <32 Data Bytes> Read scratchpad data and verify
Tx (Reset) Reset pulse
Rx (Presence) Presence pulse
Tx CCh Issue “Skip ROM” command
Tx 99h Issue “Copy Scratchpad” command
Tx 00h TA1
Tx 02h TA2
Tx 1Fh E/S
(AUTHORIZATION CODE)
Tx <8 FFh Bytes> Send dummy password
Tx (Reset) Reset pulse
Rx (Presence) Presence pulse
MASTER MODE DATA (LSB FIRST) COMMENTS
Tx (Reset) Reset pulse
Rx (Presence) Presence pulse
Tx CCh Issue “Skip ROM” command
Tx CCh Issue “Start Mission” command
Tx <8 FFh Bytes> Send dummy password
Tx FFh Send dummy byte
Tx (Reset) Reset pulse
Rx (Presence) Presence pulse
Step 3: Start the new mission.
With only a single device connected to the bus master,
the communication of step 3 looks like this:
If step 3 was successful, the MIP bit in the General
Status register is 1, the MEMCLR bit is 0, and the
Mission Start Delay counts down.