MCP79402T-I/SN Microchip Technology, MCP79402T-I/SN Datasheet - Page 10

• Manufacturer Part Number: MCP79402T-I/SN
• Description: Real Time Clock I2C GP RTCC 64B SRAM EUI-64
• Manufacturer: Microchip Technology
• Series: -r
• Type: Clock/Calendarr

Specifications of MCP79402T-I/SN

• 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-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

MCP7940X
4.0
The MCP7940X family is a highly integrated RTCC.
On-board time and date counters are driven from a low-
power oscillator to maintain the time and date. An
integrated V
the time and date and also the contents of the SRAM
during a V
4.1
The RTCC registers are contained in addresses
0x00h-0x1fh. 64 bytes of user-accessable SRAM are
located in the address range 0x20-0x5f. The SRAM
memory is a separate block from the RTCC control
and Configuration registers. All SRAM locations are
battery-backed-up during a V
locations are not accessible, MCP7940X will noACK
after the address byte if the address is out of range, as
shown in the shaded region of the memory map in
Figure
and read as ‘0’. No error checking is provided when
loading time and date registers.
• Addresses 0x00h-0x06h are the RTCC Time and
• Incorrect data can appear in the Time and Date
• Addresses 0x07h-0x09h are the device Configu-
• Addresses 0x0Ah-0x10h are the Alarm 0 regis-
• Addresses 0x11h-0x17h are the same as 0x0Bh-
• Addresses 0x18h-0x1Fh are used for the time-
The detailed memory map is shown in
DS25009B-page 10
Date registers. These are read/write registers.
Care must be taken when writing to these regis-
ters while the oscillator is running.
registers if a write is attempted during the time-
frame where these internal registers are being
incremented. The user can minimize the likeli-
hood of data corruption by insuring that any writes
to the Time and Date registers occur before the
contents of the second register reach a value of
0x59H.
ration, Calibration and ID Unlock registers.
ters. These are used to set up the Alarm 0, the
Interrupt polarity and the Alarm 0 compare.
0x11h but are used for Alarm 1.
stamp feature.
4-1. The shaded areas are not implemented
RTCC FUNCTIONALITY
RTCC MEMORY MAP
CC
CC
power failure.
switch enables the device to maintain
CC
power fail. Unused
Table
4-1.
FIGURE 4-1:
0x0A
0x00
0x06
0x07
0x09
0x10
0x11
0x17
0x18
0x1F
0x20
0x5F
0x60
0xFF
Configuration and Calibration
MEMORY MAP
SRAM (64 Bytes)
 2011 Microchip Technology Inc.
Time and Date
Time-Stamp
Alarm 0
Alarm 1