DS28E02 Maxim, DS28E02 Datasheet - Page 14

• Manufacturer Part Number: DS28E02
• Description: The DS28E02 combines 1024 bits of EEPROM with challenge-and-response authentication security implemented with the FIPS 180-3 Secure Hash Algorithm (SHA-1)
• Manufacturer: Maxim

Figure 10a. ROM Functions Flowchart
______________________________________________________________________________________
FUNCTION COMMAND
USER-DEFINED FIELD,
BUS MASTER Tx ROM
SERIAL NUMBER,
AND CUSTOM ID
FROM MEMORY AND SHA-1 FUNCTION
FAMILY CODE
ABRIDGED DATA SHEET
COMMAND?
DS28E02 Tx
DS28E02 Tx
DS28E02 Tx
READ ROM
CRC BYTE
(6 BYTES)
(1 BYTE)
RC = 0
33h
FLOWCHART (FIGURE 8)
Y
N
1-Wire SHA-1 Authenticated 1Kb
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 AND SHA-1 FUNCTION
EEPROM with 1.8V Operation
Y
Y
Y
Y
FLOWCHART (FIGURE 8)
PRESENCE PULSE
BUS MASTER Tx
RESET PULSE?
RESET PULSE
DS28E02 Tx
N
N
N
N
Y
OD
N
N
N
MASTER Tx BIT 63
DS28E02 Tx BIT 63
DS28E02 Tx BIT 63
DS28E02 Tx BIT 0
DS28E02 Tx BIT 0
MASTER Tx BIT 0
DS28E02 Tx BIT 1
DS28E02 Tx BIT 1
MASTER 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 10b
FROM FIGURE 10b
N
TO FIGURE 10b
TO FIGURE 10b
25