MCP79400-I/ST Microchip Technology, MCP79400-I/ST Datasheet - Page 19

• Manufacturer Part Number: MCP79400-I/ST
• Description: Real Time Clock I2C GP RTCC 64B SRAM ID
• Manufacturer: Microchip Technology
• Series: -r
• Type: Clock/Calendarr

Specifications of MCP79400-I/ST

• Features: Alarm, Leap Year, SRAM
• Memory Size: 64B
• Time Format: HH:MM:SS (12/24 hr)
• Date Format: YY-MM-DD-dd
• Interface: I²C
• Voltage - Supply: 1.8 V ~ 5.5 V
• Voltage - Supply, Battery: 1.3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-TSSOP (0.173", 4.40mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

FIGURE 5-5:
FIGURE 5-6:
5.3
The MCP7940X features an additional 64-bit unique ID
area.
The unique ID is located at addresses 0xF0 through
0xF7. Reading the unique ID requires the user to
simply address these bytes.
The unique ID area is protected to prevent unintended
writes to these locations. The unlock sequence is
detailed in
The unique ID can be factory programmed on some
devices to provide a unique IEEE EUI-48 or EUI-64
value. In addition, customer-provided codes can also
be programmed.
 2011 Microchip Technology Inc.
BUS ACTIVITY
MASTER
SDA LINE
BUS ACTIVITY
Unique ID
4.2.1 “Unlock
BUS ACTIVITY
MASTER
SDA LINE
BUS ACTIVITY
RANDOM READ (UNIQUE ID SHOWN)
SEQUENTIAL READ (UNIQUE ID SHOWN)
CONTROL
BYTE
Sequence”.
S
S
T
A
R
T
1 0 1 0
A
C
K
CONTROL
BYTE
1 1 1
DATA n
0
A
C
K
A
C
K
ADDRESS
BYTE
DATA n + 1
A
C
K
S
S
T
A
R
T
1 0 1 0
A
C
K
CONTROL
DATA n + 2
BYTE
1
A
C
K
A
C
K
MCP7940X
BYTE
DATA
DATA n + X
DS25009A-page 19
N
O
A
C
K
S
T
O
P
P
N
O
A
C
K
P
S
T
O
P