RS5C313 RICOH Co.,Ltd., RS5C313 Datasheet - Page 3

• Manufacturer Part Number: RS5C313
• Description: Ultra-compact Real-time Clock Ic
• Manufacturer: RICOH Co.,Ltd.

PIN DESCRIPTIONS
Pin No. Symbol
1
2
3
5
7
6
8
4
CE
SCLK
SIO
INTR
OSCIN
OSCOUT input and output
V
V
DD
SS
Chip enable input
Shift clock input
Serial input
and output
Interrupt output
Oscillation circuit
Positive power
supply input
Negative power
supply input
Name
The CE pin is used to interface with the CPU and is accessible when held at the high
level. This pin incorporates a pull-down resistor. It should be switched to the low lev-
el or opened when not accessed or when powering off the system. Holding the CE
pin at the high level for more than 2.5 seconds forces 1Hz interrupt pulses to be out-
put from the INTR pin for oscillation frequency measurement .
(No pulse is output for less than 1.5 seconds.)
The SCLK pin is used to input shift clock pulses to synchronize data input to, and
output from, the SIO pin.
The SIO pin inputs and outputs written or read data in synchronization with and out-
put shift clock pulses from the SCLK pin. The SIO pin causes high impedance when
the CE pin is held at the low level. After the CE pin is switched to the high level and
the control bits and the address bits are input from the SIO, the SIO pin performs
serial input and output operations
The INTR pin outputs cyclic interrupt pulses to the CPU. This pin functions as an
Nch open drain output even when the CE pin is held at the low level.
These pins configure an oscillation circuit by connecting a 32.768 kHz crystal
oscillator between the OSCIN and OSCOUT pins and by connecting a capacitor
between the OSCIN and V
(Any other oscillation circuit components are built into the RS5C313.)
The VDD pin is connected to a power supply and the V
ground.
SS
pins.
Description
SS
pin is connected to the
RS5C313
3