Datasheet

78K0/Kx2-L CHAPTER 10 REAL-TIME COUNTER
R01UH0028EJ0400 Rev.4.00 379
Sep 27, 2010
(7) Minute count register (MIN)
The MIN register is an 8-bit register that takes a value of 0 to 59 (decimal) and indicates the count value of minutes.
It counts up when the second 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.
Even if the second count register overflows while this register is being written, this register ignores the overflow and
is set to the value written. Set a decimal value of 00 to 59 to this register in BCD code. If a value outside this range
is set, the register value returns to the normal value after 1 period.
MIN can be set by an 8-bit memory manipulation instruction.
Reset signal generation clears this register to 00H.
Figure 10-8. Format of Minute Count Register (MIN)
Address: FFB3H After reset: 00H R/W
Symbol 7 6 5 4 3 2 1 0
MIN 0 MIN40 MIN20 MIN10 MIN8 MIN4 MIN2 MIN1
(8) Hour count register (HOUR)
The HOUR register is an 8-bit register that takes a value of 00 to 23 or 01 to 12, 21 to 32 (decimal) and indicates
the count value of hours.
It counts up when the minute 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.
Even if the minute count register overflows while this register is being written, this register ignores the overflow and
is set to the value written. Specify a decimal value of 00 to 23, 01 to 12, or 21 to 32 by using BCD code according
to the time system specified using bit 3 (AMPM) of real-time counter control register 0 (RTCC0).
If the AMPM bit value is changed, the values of the HOUR register change according to the specified time system.
If a value outside the range is set, the register value returns to the normal value after 1 period.
HOUR can be set by an 8-bit memory manipulation instruction.
Reset signal generation clears this register to 12H.
However, the value of this register is 00H if the AMPM bit (bit 3 of the RTCC0 register) is set to 1 after reset.
Figure 10-9. Format of Hour Count Register (HOUR)
Address: FFB4H After reset: 12H R/W
Symbol 7 6 5 4 3 2 1 0
HOUR 0 0 HOUR20 HOUR10 HOUR8 HOUR4 HOUR2 HOUR1
Caution Bit 5 (HOUR20) of HOUR indicates AM(0)/PM(1) if AMPM = 0 (if the 12-hour system is selected).