Datasheet

DS1921G
Thermochron iButton
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FROM FIGURE 10a
TO FIGURE 10a
TO FIGURE 10c
FROM FIGURE 10c
A5h
READ MEMORY
WITH CRC
N
Y
Y
N
MASTER Tx RESET?
CRC OK?
MASTER Tx
TA1 [T7:T0], TA2 [T15:T8]
DS1921G SETS
EMCLR = 0
MASTER Rx DATA BYTE
FROM MEMORY ADDRESS
MASTER Tx
RESET
DS1921G SETS MEMORY
ADDRESS = [T15:T0]
Y
Y
N
N
END OF PAGE?
DECISION MADE
BY MASTER
DECISION MADE
BY DS1921G
Y
N
N
END OF
MEMORY?
MASTER Rx "0"
MASTER Rx CRC-16 OF
COMMAND, ADDRESS, DATA
(1ST PASS); CRC-16 OF DATA
(SUBSEQUENT PASSES)
DS1921G
INCREMENTS
ADDRESS
COUNTER
N
Y
DS1921G CLEARS ALARM
TIMESTAMPS AND DURATIONS
MASTER Tx RESET?
Y
DS1921G CLEARS MISSION
TIMESTAMP, MISSION
SAMPLES COUNTER, MISSION
START DELAY, SAMPLE RATE
REGISTER
3Ch
CLEAR MEMORY
N
Y
DS1921G CLEARS HISTOGRAM
MEMORY
DS1921G SETS
EMCLR = 0
DS1921G SETS
MEMCLR = 1
EMCLR = 1?
DS1921G SETS
EMCLR = 0
DS1921G SETS
MEMORY ADDRESS = [T15:T0]
DS1921G
INCREMENTS
ADDRESS
COUNTER
F0h
READ MEMORY?
N
Y
Y
N
Y
N
MASTER Tx RESET?
END OF
MEMORY?
MASTER Rx
TA1 [T7:T0], TA2 [T15:T8]
MASTER Rx DATA BYTE FROM
MEMORY ADDRESS
MASTER Rx
00 BYTE
Figure 10b. Memory/Control Function Flowchart