R2025S/D
• Reading Time and Calendar Data
(1) Ordinary Process of Reading Time and Calendar Data
*1) When reading to clock and calendar counters, do not insert Stop
Condition until all times from second to year have been written to prevent
*1)
*2)
Start Condition
error in writing time. (Detailed in "P.27 Data Transmission under Special
Condition".
*2) Take care so that process from Start Condition to Stop Condition will be
complete within 0.5sec. (Detailed in "P.27 Data Transmission under
Special Condition".
Read from Time Counter
and Calendar Counter
Stop Condition
(2) Basic Process of Reading Time and Calendar Data with Periodic Interrupt Function
*1) This step is intended to select the level mode as a
Set Periodic Interrupt
Cycle Selection Bits
*1)
waveform mode for the periodic interrupt function.
*2) This step must be completed within 0.5 second.
*3) 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 in CPU
No
Other Interrupt
Processes
CTFG=1?
Yes
*2)
Read from Time Counter
and Calendar Counter
*3)
Control Register 2
(X1X1X011)
←
43
RICOH [ RICOH ELECTRONICS DEVICES DIVISION ]
