MCP7940N-I/SN Microchip Technology, MCP7940N-I/SN Datasheet - Page 8

• Manufacturer Part Number: MCP7940N-I/SN
• Description: I2C GP RTCC, 64B SRAM 8 SOIC 3.90mm (.150") TUBE
• Manufacturer: Microchip Technology
• Series: -r
• Type: Clock/Calendarr

Specifications of MCP7940N-I/SN

• 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-SOIC (0.154", 3.90mm Width)
• Function: Clock, Calendar, Alarm, Battery Backup
• Rtc Memory Size: 64 B
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 1.8 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Rtc Bus Interface: 2-Wire, I2C
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

MCP7940N
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 for accessing the SRAM and RTCC
registers are set to ‘1101111’. 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
selected. The next byte received defines the address of
FIGURE 3-3:
DS25010A-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.
X = Don’t Care
ACKNOWLEDGE TIMING
ADDRESS SEQUENCE BIT ASSIGNMENTS
2
1
SRAM RTCC CONTROL BYTE
CONTROL
CODE
1
3
Data from transmitter
0
4
1
(Figure
1
5
1
3-2).
1
6
R/W
7
Acknowledge
the data byte
transferred first, followed by the Least Significant bits
(LSb).
Following the Start condition, the MCP7940N monitors
the SDA bus, checking the device type identifier being
transmitted. Upon receiving an ‘1101111’ code, the
slave device outputs an Acknowledge signal on the
SDA line. Depending on the state of the R/W bit, the
MCP7940N will select a read or write operation.
8
X
Bit
•
9
ADDRESS BYTE
•
1
(Figure
•
Receiver must release the SDA line at this point
so the Transmitter can continue sending data.
Data from transmitter
•
2
3-3). The upper address bits are
•
 2011 Microchip Technology Inc.
•
3
A
0