RX5C348A 参数 Datasheet PDF下载

Rx5C348A/B

In the pulse mode, the increment of the second counter is delayed by approximately 92

µ

s from the

falling edge of clock pulses. Consequently, time readings immediately after the falling edge of clock

pulses may appear to lag behind the time counts of the real-time clocks by approximately 1 second.

Rewriting the second counter will reset the other time counters of less than 1 second, driving the

/INTR pin low.

*2) Level Mode:

Periodic interrupt signals are output with selectable interrupt cycle settings of 1 second, 1 minute, 1

hour, and 1 month. The increment of the second counter is synchronized with the falling edge of

periodic interrupt signals. For example, periodic interrupt signals with an interrupt cycle setting of 1

second are output in synchronization with the increment of the second counter as illustrated in the

timing chart below.

CTFG Bit

/INTR Pin

Setting CTFG bit to 0

(Increment of

second counter)

(Increment of

second counter)

Setting CTFG bit to 0

(Increment of

second counter)

*1), *2) When the oscillation adjustment circuit is used, the interrupt cycle will fluctuate once per 20sec. as

follows:

Pulse Mode: The “L” period of output pulses will increment or decrement by a maximum of

±

3.784ms. For

example, 1-Hz clock pulses will have a duty cycle of 50

±

0.3784%.

Level Mode: A periodic interrupt cycle of 1 second will increment or decrement by a maximum of

±

3.784 ms.

32-kHz CLOCK OUTPUT

For the Rx5C348A, 32.768-kHz clock pulses are output from the 32KOUT pin when either the /CLEN1 bit in

the Control Register 2 or the /CLEN2 bit in the Control Register 1 is set to 0. When both the /CLEN1 and

/CLEN2 bits are set to 0, the 32KOUT pin output is driven high (off).

/CLEN1

(D3 at Address Fh)

/CLEN2

(D4 at Address Eh)

1

0(Default)

*

1

*

0(Default)

32KOUT PIN

(N-channel Open Drain)

OFF(H)

Clock pulses

The 32KOUT pin output is synchronized with the /CLEN1 and /CLEN2 bit settings as illustrated in the timing

chart below.

/CLEN1or2

32KOUT PIN

Max.62.0µs

For the Rx5C348B, 32.768-kHz clock pulses are output from the 32KOUT pin regardless of such internal

register settings.

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Rev.2.01

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