DS1972 Maxim, DS1972 Datasheet - Page 14

• Manufacturer Part Number: DS1972
• Description: The DS1972 is a 1024-bit, 1-Wire® EEPROM chip organized as four memory pages of 256 bits each in a rugged iButton® package
• Manufacturer: Maxim

1024-Bit EEPROM iButton
Figure 9a. ROM Functions Flowchart
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FUNCTION COMMAND
BUS MASTER Tx ROM
SERIAL NUMBER
FAMILY CODE
COMMAND?
READ ROM
DS1972 Tx
DS1972 Tx
DS1972 Tx
CRC BYTE
(6 BYTES)
(1 BYTE)
RC = 0
33h
Y
FROM MEMORY FUNCTIONS
FLOWCHART (FIGURE 7)
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
Y
Y
Y
Y
TO MEMORY FUNCTIONS
FLOWCHART (FIGURE 7)
PRESENCE PULSE
BUS MASTER Tx
RESET PULSE?
RESET PULSE
N
N
N
DS1972 Tx
N
Y
OD
N
N
N
MASTER Tx BIT 63
DS1972 Tx BIT 63
DS1972 Tx BIT 63
MASTER Tx BIT 0
MASTER Tx BIT 1
DS1972 Tx BIT 0
DS1972 Tx BIT 0
DS1972 Tx BIT 1
DS1972 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
COMMAND?
SKIP ROM
RC = 0
CCh
Y
FROM FIGURE 9b
FROM FIGURE 9b
N
TO FIGURE 9b
TO FIGURE 9b