DS1922T Maxim, DS1922T Datasheet - Page 15

• Manufacturer Part Number: DS1922T
• Description: The DS1922L/T temperature logger iButtons® are rugged, self-sufficient systems that measure temperature and record the result in a protected memory section
• Manufacturer: Maxim

Figure 2. Hierarchical Structure for 1-Wire Protocol
Figure 3. 64-Bit Lasered ROM
Figure 4. 1-Wire CRC Generator
X
0
MSB
MSB
STAGE
1ST
MASTER
BUS
MEMORY/CONTROL FUNCTION
CRC CODE
X
DS1922L/DS1922T-SPECIFIC
1
8-BIT
FUNCTION COMMANDS
COMMAND LEVEL:
______________________________________________________________________________________
STAGE
2ND
COMMANDS
1-Wire ROM
Temperature Logger iButton with 8KB
LSB
X
2
MSB
STAGE
3RD
1-Wire NET
X
3
STAGE
4TH
AVAILABLE COMMANDS:
READ ROM
MATCH ROM
SEARCH ROM
CONDITIONAL SEARCH ROM
SKIP ROM
RESUME
OVERDRIVE-SKIP ROM
OVERDRIVE-MATCH ROM
WRITE SCRATCHPAD
READ SCRATCHPAD
COPY SCRATCHPAD WITH PW
READ MEMORY WITH PW AND CRC
CLEAR MEMORY WITH PW
FORCED CONVERSION
START MISSION WITH PW
STOP MISSION WITH PW
POLYNOMIAL = X
OTHER DEVICES
48-BIT SERIAL NUMBER
DS1922L/DS1922T
X
4
8
+ X
5
STAGE
5TH
+ X
4
+ 1
DATA FIELD AFFECTED:
64-BIT ROM, RC-FLAG
64-BIT ROM, RC-FLAG
64-BIT ROM, RC-FLAG
64-BIT ROM, RC-FLAG, ALARM FLAGS, SEARCH CONDITIONS
RC-FLAG
RC-FLAG
RC-FLAG, OD-FLAG
64-BIT ROM, RC-FLAG, OD-FLAG
256-BIT SCRATCHPAD, FLAGS
256-BIT SCRATCHPAD
512-BYTE DATA MEMORY, REGISTERS, FLAGS, PASSWORDS
MEMORY, REGISTERS, PASSWORDS
MISSION TIMESTAMP, MISSION SAMPLES COUNTER,
MEMORY ADDRESSES 020Ch TO 020Dh
FLAGS, TIMESTAMP, MEMORY ADDRESSES
FLAGS
START DELAY, ALARM FLAGS, PASSWORDS
020Ch TO 020Dh (WHEN LOGGING)
Data-Log Memory
X
5
STAGE
6TH
LSB
X
6
MSB
STAGE
7TH
8-BIT FAMILY CODE
(41h)
X
INPUT DATA
7
STAGE
8TH
LSB
LSB
X
8
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