Datasheet

DS1922L/DS1922T
Temperature Logger iButton with 8KB
Data-Log Memory
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DS1922 Tx
PRESENCE PULSE
BUS MASTER Tx
RESET PULSE
BUS MASTER Tx ROM
FUNCTION COMMAND
DS1922 Tx
CRC BYTE
DS1922 Tx
FAMILY CODE
(1 BYTE)
DS1922 Tx
SERIAL NUMBER
(6 BYTES)
OD = 0
RC = 0
MASTER Tx BIT 0
RC = 0 RC = 0 RC = 0
Y
OD
RESET PULSE?
YY
Y
Y
Y
Y
N
33h
READ ROM
COMMAND?
N
55h
MATCH ROM
COMMAND?
BIT 0 MATCH? BIT 0 MATCH?
N
N N
N N
N N
F0h
SEARCH ROM
COMMAND?
N
ECh
CONDITIONAL SEARCH
COMMAND?
N
Y
RC = 1
MASTER Tx BIT 1
MASTER Tx BIT 63
BIT 1 MATCH?
BIT 63 MATCH?
Y
Y
RC = 1
FROM MEMORY/CONTROL FUNCTION
FLOWCHART (FIGURE 9)
DS1922 Tx BIT 0
DS1922 Tx BIT 0
MASTER Tx BIT 0
BIT 1 MATCH?
BIT 63 MATCH?
DS1922 Tx BIT 1
DS1922 Tx BIT 1
MASTER Tx BIT 1
DS1922 Tx BIT 63
DS1922 Tx BIT 63
MASTER Tx BIT 63
Y
BIT 0 MATCH?
N
N
N
Y
Y
RC = 1
DS1922 Tx BIT 0
DS1922 Tx BIT 0
MASTER Tx BIT 0
CONDITION
MET?
N
Y
BIT 1 MATCH?
BIT 63 MATCH?
DS1922 Tx BIT 1
DS1922 Tx BIT 1
MASTER Tx BIT 1
DS1922 Tx BIT 63
DS1922 Tx BIT 63
MASTER Tx BIT 63
Y
FROM FIGURE 11b
TO FIGURE 11b
TO FIGURE 11b
FROM FIGURE 11b
TO MEMORY/CONTROL FUNCTION
FLOWCHART (FIGURE 9)
Figure 11a. ROM Functions Flowchart