RL78/G1A CHAPTER 7 REAL-TIME CLOCK
7.4 Real-time Clock Operation
7.4.1 Starting operation of real-time clock
Figure 7-19. Procedure for Starting Operation of Real-time Clock
Start
INTRTC = 1?
RTCE = 0
Stops counter operation.
Setting AMPM, CT2 to CT0 Selects 12-/24-hour system and interrupt (INTRTC).
Setting SEC
Sets second count register.
Setting MIN Sets minute count register.
No
Yes
Setting HOUR Sets hour count register.
Setting WEEK Sets week count register.
Setting DAY Sets day count register.
Setting MONTH Sets month count register.
Setting YEAR Sets year count register.
Setting SUBCUD
Note 2
Sets watch error correction register.
Clearing IF flags of interrupt Clears interrupt request flags (RTCIF).
Clearing MK flags of interrupt Clears interrupt mask flags (RTCMK).
RTCE = 1
Note 3
Starts counter operation.
End
RTCEN = 1
Note 1
Supplies input clock.
Setting WUTMMCK0
Sets f
RTC
Notes 1. First set the RTCEN bit to 1, while oscillation of the count clock (f
RTC) is stable.
2. Set up the SUBCUD register only if the watch error must be corrected. For details about how to
calculate the correction value, see 7.4.6 Example of watch error correction of real-time clock.
3. Confirm the procedure described in 7.4.2 Shifting to HALT/STOP mode after starting operation
when shifting to HALT/STOP mode without waiting for INTRTC = 1 after RTCE = 1.
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