DS1923 Maxim, DS1923 Datasheet - Page 39

• Manufacturer Part Number: DS1923
• Description: The DS1923 temperature/humidity logger iButton® is a rugged, self-sufficient system that measures temperature and/or humidity and records the result in a protected memory section
• Manufacturer: Maxim

Figure 11a. ROM Functions Flowchart
Hygrochron Temperature/Humidity Logger
______________________________________________________________________________________
FUNCTION COMMAND
BUS MASTER Tx ROM
SERIAL NUMBER
FAMILY CODE
COMMAND?
READ ROM
DS1923 Tx
DS1923 Tx
DS1923 Tx
CRC BYTE
(6 BYTES)
FUNCTION FLOWCHART (FIGURE 9)
(1 BYTE)
RC = 0
33h
FROM MEMORY/CONTROL
Y
iButton with 8KB Data-Log Memory
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
FUNCTION FLOWCHART (FIGURE 9)
Y
Y
Y
Y
TO MEMORY/CONTROL
PRESENCE PULSE
BUS MASTER Tx
RESET PULSE?
RESET PULSE
N
N
N
DS1923 Tx
Y
N
OD
N
N
N
MASTER Tx BIT 63
DS1923 Tx BIT 63
DS1923 Tx BIT 63
MASTER Tx BIT 0
MASTER Tx BIT 1
DS1923 Tx BIT 0
DS1923 Tx BIT 0
DS1923 Tx BIT 1
DS1923 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
DS1923 Tx BIT 63
DS1923 Tx BIT 63
MASTER Tx BIT 0
MASTER Tx BIT 1
DS1923 Tx BIT 0
DS1923 Tx BIT 0
DS1923 Tx BIT 1
DS1923 Tx BIT 1
BIT 63 MATCH?
BIT 0 MATCH?
BIT 1 MATCH?
COMMAND?
CONDITION
RC = 0
RC = 1
MET?
ECh
Y
Y
Y
Y
Y
N
FROM FIGURE 11b
FROM FIGURE 11b
TO FIGURE 11b
TO FIGURE 11b
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