R2025S/D
(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:
*1) This step is intended to select the level
Control Register 1
mode as a waveform mode for the
periodic interrupt function.
←
(XXXX0100)
*2) This step must be completed within 0.5
sec.
Control Register 2
(X1X1X011)
←
*1)
*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.
Generate interrupt to CPU
CTFG=1?
Other interrupts
Processes
No
No
Yes
*2)
Sec.=00?
Yes
*3)
Read Min.,Hr.,Day,
and Day-of-week
Use Previous Min.,Hr.,
Day,and Day-of-week data
Control Register 2
(X1X1X011)
*4)
←
44
RICOH [ RICOH ELECTRONICS DEVICES DIVISION ]
