DS1347_13 Datasheet, PDF (12/17 Pages) Maxim Integrated Products – Low-Current, SPI-Compatible Real-Time Clock

DS1347
Low-Current, SPI-Compatible
Real-Time Clock
BIT 7
0
0
BIT 6
1
BIT 5
10 MINUTES
1
BIT 4
1
BIT 3
1
BIT 7
12/24
1
BIT 6
0
0
BIT 5
AM/PM
20 HR
1
BIT 4
10 HR
1
BIT 3
1
BIT 7
0
0
BIT 6
0
0
BIT 5
BIT 4
10 DATE
1
1
BIT 3
1
BIT 7
0
0
BIT 6
0
0
BIT 5
0
0
BIT 4
10 MO
1
BIT 3
1
BIT 7
0
0
BIT 6
0
0
BIT 5
0
0
BIT 4
0
0
BIT 3
0
0
BIT 7
1
BIT 6
BIT 5
10 YEAR
1
1
BIT 4
1
BIT 3
1
Alarm Minutes Register (1Bh)
BIT 2
BIT 1
MINUTES
1
1
BIT 0
1
Alarm Hours Register (1Dh)
BIT 2
BIT 1
BIT 0
HOURS
1
1
1
Alarm Date Register (1Fh)
BIT 2
1
DATE
BIT 1
1
BIT 0
1
Alarm Month Register (21h)
BIT 2
BIT 1
MONTH
1
1
BIT 0
1
Alarm Day Register (23h)
BIT 2
1
BIT 1
DAY
1
BIT 0
1
Alarm Year Register (25h)
BIT 2
1
YEAR
BIT 1
1
BIT 0
1
SPI-Compatible Serial Interface
Interface the device with a microcontroller using a serial,
4-wire, SPI interface. SPI is a synchronous bus for
address and data transfer, and is used with Motorola or
other microcontrollers that have an SPI port. Four con-
nections are required for the interface: DOUT (serial-
data out); DIN (serial-data in); SCLK (serial clock); and
CS (chip select). In an SPI application, the device acts
as a slave device and the microcontroller acts as the
master. CS is asserted low by the microcontroller to initi-
ate a transfer, and deasserted high to terminate a trans-
fer. DIN transfers input data from the microcontroller to
the device. DOUT transfers output data from the device
to the microcontroller. A shift clock, SCLK, is used to
synchronize data movement between the microcon-
troller and the device. SCLK, which is generated by the
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Maxim Integrated