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CHAPTER 9 REAL-TIME COUNTER
User’s Manual U19780EJ2V0UD
297
(10) Month count register (MONTH)
The MONTH register is an 8-bit register that takes a value of 1 to 12 (decimal) and indicates the count value
of months.
It counts up when the day counter overflows.
When data is written to this register, it is written to a buffer and then to the counter up to 2 clocks (32.768 kHz)
later. Set a decimal value of 01 to 12 to this register in BCD code. If a value outside the range is set, the
register value returns to the normal value after 1 period.
MONTH can be set by an 8-bit memory manipulation instruction.
Reset signal generation clears this register to 01H.
Figure 9-11. Format of Month Count Register (MONTH)
Address: FF77H After reset: 01H R/W
Symbol
7 6 5 4 3 2 1 0
MONTH
0
0
0
MONTH10 MONTH8 MONTH4 MONTH2 MONTH1
(11) Year count register (YEAR)
The YEAR register is an 8-bit register that takes a value of 0 to 99 (decimal) and indicates the count value of
years.
It counts up when the month counter overflows.
Values 00, 04, 08, …, 92, and 96 indicate a leap year.
When data is written to this register, it is written to a buffer and then to the counter up to 2 clocks (32.768 kHz)
later. Set a decimal value of 00 to 99 to this register in BCD code. If a value outside the range is set, the
register value returns to the normal value after 1 period.
YEAR can be set by an 8-bit memory manipulation instruction.
Reset signal generation clears this register to 00H.
Figure 9-12. Format of Year Count Register (YEAR)
Address: FF78H After reset: 00H R/W
Symbol
7 6 5 4 3 2 1 0
YEAR YEAR80 YEAR40 YEAR20 YEAR10 YEAR8 YEAR4 YEAR2 YEAR1