PRELIMINARY

RV5C387A

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(3) Applied Process of Reading Time and Calendar Data with Periodic Interrupt Function

Time data need not be read from all the time counters when used for such ordinary purposes as time count indication.

This

applied process can be used to read time and calendar data with substantial reductions in the load involved in such reading.

For Time Indication in "Day-of-Month, Day-of-week, Hour, Minute, and Second"

Format:

*2)

Other interrupts

Processes

Control Register 1

←

(XXXX0100)

Control Register 2

←

(X1X1X011)

Sec.=00?

Yes

No

Use Previous Min.,Hr.,

Day,and Day-of-week data

Generate interrupt to CPU

*1)

*3)

CTFG=1?

Control Register 2

←

(X1X1X011)

Yes

Read Min.,Hr.,Day,

and Day-of-week

*4)

No

*1) This step is intended to select the level

mode as a waveform mode for the

periodic interrupt function.

*2) This step must be completed within 0.5

sec.

*3) This step is intended to read time data

from all the time counters only in the

first session of reading time data after

writing time data.

*4) This step is intended to set the CTFG

bit to 0 in the Control Register 2 to

cancel an interrupt to the CPU.