Datasheet
MCP79410/MCP79411/MCP79412
DS20002266E-page 24 2010-2013 Microchip Technology Inc.
FIGURE 8-4: UNIQUE ID UNLOCK SEQUENCE
BUS ACTIVITY
MASTER
SDA LINE
BUS ACTIVITY
S
T
A
R
T
CONTROL
BYTE
ADDRESS
BYTE
DATA
S
T
O
P
A
C
K
A
C
K
A
C
K
S
1101 01
11
P
0
BUS ACTIVITY
MASTER
SDA LINE
BUS ACTIVITY
S
T
A
R
T
CONTROL
BYTE
ADDRESS
BYTE
DATA BYTE 0
S
T
O
P
A
C
K
A
C
K
A
C
K
DATA BYTE 7
A
C
K
S 1010 0
P
1
00 01 00 1 0 1 0 1 01 01
BUS ACTIVITY
MASTER
SDA LINE
BUS ACTIVITY
S
T
A
R
T
CONTROL
BYTE
ADDRESS
BYTE
DATA
S
T
O
P
A
C
K
A
C
K
A
C
K
S
1101 0
1
11
P
000 01001 10101010
1110000111
REGISTER 8-2: UNLOCK ID 0X09
W-0
UNIQUE UNLOCK ID SEQUENCE
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set “0” = Bit is clear “X” = Bit is unknown
bit 7-0
UNLOCK ID: This is the unlock sequence address. To unlock write access to the unique ID area in
the EEPROM, a sequence must be written to this address in separate commands. The process is
shown in Figure 8-4.