MCP79412T-I/ST Microchip Technology, MCP79412T-I/ST Datasheet - Page 8

• Manufacturer Part Number: MCP79412T-I/ST
• Description: Real Time Clock I2C GP RTCC 1Kb EE 64B SRAM EUI-64
• Manufacturer: Microchip Technology
• Series: -r
• Type: Clock/Calendarr

Specifications of MCP79412T-I/ST

• Function: Clock/Calendar
• Rtc Memory Size: 64 Byte
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Rtc Bus Interface: I2C
• Supply Current: 1 uA
• Features: Alarm, Leap Year, NVSRAM, Square Wave Output, Unique ID
• 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

MCP7941X
FIGURE 3-2:
3.1.2
A control byte is the first byte received following the
Start condition from the master device
The control byte consists of a control code; for the
MCP7941X this is set as ‘1010111X’ for read (0xAF)
and write (0xAE) operations for the EEPROM.
The control byte for accessing the SRAM and RTCC
registers are set to ‘1101111’ (0xDF for a read, 0xDE
for a write). The RTCC registers and the SRAM share
the same address space.
The last bit of the control byte defines the operation to
be performed. When set to a ‘1’ a read operation is
selected, and when set to a ‘0’ a write operation is
FIGURE 3-3:
DS22266C-page 8
SCL
SDA
DEVICE ADDRESSING AND OPERATION
1
Transmitter must release the SDA line at this point
allowing the Receiver to pull the SDA line low to
acknowledge the previous eight bits of data.
1
ACKNOWLEDGE TIMING
ADDRESS SEQUENCE BIT ASSIGNMENTS
1
CONTROL
SRAM RTCC CONTROL BYTE
2
EEPROM CONTROL BYTE
CONTROL
CODE
0
CODE
1
1
3
Data from transmitter
0
0
1
4
1
1
1
(Figure
1
5
1
1
R/W
3-2).
R/W
6
7
{“A7” is ‘0’ for normal EEPROM
operations, but is used to access unique ID
location and STATUS register.)
A7
A7
Acknowledge
selected. The next byte received defines the address of
the data byte
transferred first, followed by the Least Significant bits
(LSb).
Following the Start condition, the MCP7941X monitors
the SDA bus, checking the device type identifier being
transmitted.
‘1101111’ code, the slave device outputs an
Acknowledge signal on the SDA line. Depending on the
state of the R/W bit, the MCP7941X will select a read
or write operation.
8
•
•
Bit
ADDRESS BYTE
ADDRESS BYTE
•
9
•
•
•
1
(Figure
Receiver must release the SDA line at this point
so the Transmitter can continue sending data.
Upon
•
Data from transmitter
•
•
 2010-2011 Microchip Technology Inc.
•
2
3-3). The upper address bits are
receiving
•
•
A
0
3
A
0
an
‘1010111’
or