RV5C339A_03 Datasheet, PDF (44/46 Pages) RICOH electronics devices division – 3-WIRE SERIAL INTERFACE REAL-TIME CLOCK IC WITH VOLTAGE MONITORING FUNCTION

RV5C339A
8.3 Reading Time and Calendar Data
8.3-1 Ordinary Process of Reading Time and Calendar Data
*1) This step of waiting is detailed in “1.5 Considerations in Reading and
Writing Time Data”.
Wait for 31µs
*¹
Read from Time Counter
and Calendar Counter
8.3-2 Basic Process of Reading Time and Calendar Data Synchronized with Periodic Interrupt
Set Periodic Interrupt
Cycle Selection Bits
*¹
Generate Interrupt in CPU
NO
CTFG=1?
YES
Read from Time Counter
Other Interrupt
and Calendar Counter *^{2 Processes}
*1) This step is intended to select the level mode as a waveform mode for the
periodic interrupt function.
*2) If this step is completed within 1 second, the step of waiting described in
“8.3-1 Ordinary Process of Reading Time and Calendar Data” above need
not be conducted. This step is detailed in “1.5 Considerations in Reading
and Writing Time Data”.
*3) This step is intended to set the CTFG bit to 0 in the control register 2 to
cancel an interrupt to the CPU.
Write “×,1,×,1,×,0,1,1” _*³
to Control Register 2
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