RV5C338A-E2 Просмотр технического описания (PDF) - RICOH Co.,Ltd.

Номер в каталоге

Компоненты Описание

Список матч

RV5C338A-E2

3-WIRE SERIAL INTERFACE REAL-TIME CLOCK ICS WITH VOLTAGE MONITORING FUNCTION

RICOH Co.,Ltd. 

R×5C338A

5. Oscillation Halt Sensing Function and Supply Voltage Monitoring Function

The R×5C338A incorporate an oscillation halt sensing circuit equipped with internal registers configured to record

any past oscillation halt, thereby identifying whether they are powered on from 0 volts or battery backed-up. As

such, the oscillation halt sensing circuit is useful for judging the validity of time data.

The R×5C338A also incorporate a supply voltage monitoring circuit equipped with internal registers configured to

record any drop in supply voltage below a certain threshold value. Supply voltage monitoring threshold settings can

be selected between 2.1 and 1.6 volts through internal register settings.

The oscillation halt sensing circuit is configured to confirm the established invalidation of time data in contrast to

the supply voltage monitoring circuit intended to confirm the potential invalidation of time data. Further, the supply

voltage monitoring circuit can be applied to battery supply voltage monitoring.

6. Periodic Interrupt Function

The R×5C338A incorporate a periodic interrupt circuit configured to generate periodic interrupt signals aside from

interrupt signals generated by the alarm circuit for output from the INTR pin. Periodic interrupt signals have five

selectable frequency settings of 2Hz (once per 0.5 seconds), 1Hz (once per 1 second), 1/60Hz (once per 1 minute),

1/3600Hz (once per 1 hour), and monthly (the first day of every month). Further, periodic interrupt signals also

have two selectable waveforms of a normal pulse form (with a frequency of 2Hz or 1Hz) and special form adapted to

interruption from the CPU in the level mode (with second, minute, hour, and month interrupts). The register

records of periodic interrupt signals can be monitored by using a polling function.

7. 32-kHz Clock Output Function

The R×5C338A incorporate a 32-kHz clock circuit configured to generate clock pulses with the oscillation frequency

of a 32.768-kHz crystal oscillator for output from the 32KOUT pin. The 32KOUT pin is CMOS output and the output

from this pin 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 it 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.

8

Share Link: