DS1922T Maxim, DS1922T Datasheet - Page 39

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