Rx5C348A/B
ꢀ PIN DESCRIPTION
Symbol
CE
Item
Chip enable
Input
Description
The CE pin is used for interfacing with the CPU. Should be held high to
allow access to the CPU. Incorporates a pull-down resistor. Should be
held low or open when the CPU is powered off. Allows a maximum input
voltage of 5.5v regardless of supply voltage.
SCLK
SI
Serial Clock
Input
The SCLK pin is used to input clock pulses synchronizing the input and
output of data to and from the SI and SO pins. Allows a maximum input
voltage of 5.5v regardless of supply voltage.
The SI pin is used to input data intended for writing in synchronization with
the SCLK pin. CMOS input. Allows a maximum input voltage of 5.5v
regardless of supply voltage.
Serial Input
SO
Serial Output
The SO pin is used to output data intended for reading in synchronization
with the SCLK pin. CMOS output.
/INTR
Interrupt
Output
The /INTR pin is used to output alarm interrupt (Alarm_W) and alarm
interrupt (Alarm_D) and output periodic interrupt signals to the CPU signals.
Disabled at power-on from 0V. N-channel open drain output. Allows a
maximum pull-up voltage of 5.5v regardless of supply voltage.
The 32KOUT pin is used to output 32.768-kHz clock pulses. Enabled at
power-on from 0 volts. Nch. open drain output. The Rx5C348A is designed
to disable 32-kHz clock output in response to a command from the host
computer and the Rx5C348B is designed to keep 32-kHz output enabled.
The OSCIN and OSCOUT pins are used to connect the 32.768-kHz crystal
oscillator (with all other oscillation circuit components built into the
Rx5C348A/B).
32KOUT
32kHz Clock
Output
OSCIN
OSCOUT
Oscillation
Circuit
Input / Output
Positive/Negative
Power
VDD
VSS
The VDD pin is connected to the power supply. The VSS pin is grounded.
Supply Input
12345
Rev.2.01
- 3 -
RICOH [ RICOH ELECTRONICS DEVICES DIVISION ]
