Datasheet

DS1922L/DS1922T
Temperature Logger iButton with 8KB
Data-Log Memory
32 ______________________________________________________________________________________
FROM FIGURE 9a
TO FIGURE 9a
TO FIGURE 9c
FROM FIGURE 9c
69h
READ MEMORY [WITH
PW] AND CRC
N
N
Y
Y
N
N
END OF MEMORY?
MASTER Tx RESET?
CRC OK?
MASTER Tx
64 BITS [PASSWORD]
MASTER Tx
TA1 [T7:T0], TA2 [T15:T8]
DS1922 SETS
MEMORY ADDRESS = [T15:T0]
MASTER Rx DATA BYTE FROM
MEMORY ADDRESS
Y
N
N
N
END OF PAGE?
DECISION MADE
BY MASTER
DECISION MADE
BY DS1922
Y
N
Y
Y
MASTER Tx RESET?
Y
PASSWORD
ACCEPTED?
MASTER Tx RESET
MASTER Rx "1"s
MASTER Rx CRC-16 OF
COMMAND, ADDRESS, DATA
(1ST PASS); CRC-16 OF DATA
(SUBSEQUENT PASSES)
DS1922
INCREMENTS
ADDRESS
COUNTER
N
Y
MASTER Tx
FFh DUMMY BYTE
MASTER Tx
64 BITS [PASSWORD]
DS1922 SETS
MEMCLR = 1
Y
MISSION IN
PROGRESS?
N
N
Y
MASTER Tx RESET?
Y
PASSWORD
ACCEPTED?
DS1922 CLEARS
MISSION TIMESTAMP,
MISSION SAMPLES COUNTER,
ALARM FLAGS
96h
CLEAR MEMORY
[WITH PW]
N
N
Y
MASTER Tx
FFh DUMMY BYTE
DS1922 COPIES RESULT TO
ADDRESS 020C/Dh
DS1922 PERFORMS A
TEMPERATURE CONVERSION
Y
MISSION IN
PROGRESS?
N
MASTER Tx RESET?
Y
55h
FORCED CONVERSION?
Figure 9b. Memory/Control Function Flowchart (continued)