R2023K/T
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Periodic Interrupt Function
The R2023K/T incorporates the periodic interrupt circuit configured to generate periodic interrupt signals aside
from interrupt signals generated by the alarm interrupt circuit for output from the INTRA pin. Periodic interrupt
signals have five selectable frequency settings of 2 Hz (once per 0.5 seconds), 1 Hz (once per 1 second), 1/60 Hz
(once per 1 minute), 1/3600 Hz (once per 1 hour), and monthly (the first day of every month). Further, periodic
interrupt signals also have two selectable waveforms, a normal pulse form (with a frequency of 2 Hz or 1 Hz) and
special form adapted to interruption from the CPU in the level mode (with second, minute, hour, and month
interrupts). The condition of periodic interrupt signals can be monitored with using a polling function.
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32kHz Clock Output
The R2023K/T incorporates a 32-kHz clock circuit configured to generate clock pulses with the oscillation
frequency of a 32.768kHz crystal oscillator for output from the 32KOUT pin. The 32KOUT pin is CMOS push-pull
output and the output is enabled and disabled when the CLKC pin is held high, and low or open, respectively.
The 32-kHz clock output can be disabled by certain register settings but cannot be disabled without manipulation of
any two registers with different addresses to prevent disabling in such events as the runaway of the CPU. The
32-kHz clock circuit is enabled at power-on, when the CLKC pin is held high.
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RICOH [ RICOH ELECTRONICS DEVICES DIVISION ]
