Datasheet
CHAPTER 9 REAL-TIME COUNTER
User’s Manual U18698EJ1V0UD
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Table 9-2. Displayed Time Digits
24-Hour System 12-Hour System 24-Hour System 12-Hour System
00 12 (AM12) 12 32 (PM12)
01 01 (AM1) 13 21 (PM1)
02 02 (AM2) 14 22 (PM2)
03 03 (AM3) 15 23 (PM3)
04 04 (AM4) 16 24 (PM4)
05 05 (AM5) 17 25 (PM5)
06 06 (AM6) 18 26 (PM6)
07 07 (AM7) 19 27 (PM7)
08 08 (AM8) 20 28 (PM8)
09 09 (AM9) 21 29 (PM9)
10 10 (AM10) 22 30 (PM10)
11 11 (AM11) 23 31 (PM11)
(3) Real-time counter control register 1 (RTCC1)
The RTCC1 register is an 8-bit register that is used to control the alarm interrupt function and the wait time of
the counter.
RTCC1 can be set by a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation clears this register to 00H.
Figure 9-4. Format of Real-Time Counter Control Register 1 (RTCC1) (1/2)
Address: FF8AH After reset: 00H R/W
Symbol <7> <6> 5 <4> <3> 2 <1> <0>
RTCC1 WALE WALIE 0 WAFG RIFG 0 RWST RWAIT
WALE Alarm operation control
0 Match operation is invalid.
1 Match operation is valid.
To set the registers of alarm (WALIE flag of RTCC1, ALARMWM register, ALARMWH register, and ALARMWW
register), disable WALE (clear it to “0”).
WALIE Control of alarm interrupt (INTRTC) function operation
0 Does not generate interrupt on matching of alarm.
1 Generates interrupt on matching of alarm.
WAFG Alarm detection status flag
0 Alarm mismatch
1 Detection of matching of alarm
This is a status flag that indicates detection of matching with the alarm. It is valid only when WALE = 1 and is set to
“1” one clock (32.768 kHz) after matching of the alarm is detected. This flag is cleared when “0” is written to it.
Writing “1” to it is invalid.