Renesas rl78 User Manual
RL78/G1A
CHAPTER 7 REAL-TIME CLOCK
7.3.5 Second count register (SEC)
The SEC register is an 8-bit register that takes a value of 0 to 59 (decimal) and indicates the count value of seconds.
It counts up when the internal counter (16-bit) overflows.
When data is written to this register, it is written to a buffer and then to the counter up to two cycles of f
RTC
later. Set a
decimal value of 00 to 59 to this register in BCD code.
<R>
The SEC register can be set by an 8-bit memory manipulation instruction.
Reset signal generation clears this register to 00H.
Remark The internal counter (16 bits) is cleared when the second count register (SEC) is written.
<R>
Figure 7-6. Format of Second Count Register (SEC)
Address: FFF92H After reset: 00H R/W
Symbol
7 6 5 4 3 2 1 0
SEC
0 SEC40
SEC20
SEC10 SEC8 SEC4 SEC2 SEC1
Caution When it reads or writes from/to the register while the counter is in operation (RTCE = 1), follow
the procedures described in 7.4.3 Reading/writing real-time clock.
7.3.6 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 two cycles of f
RTC
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.
<R>
The MIN register can be set by an 8-bit memory manipulation instruction.
Reset signal generation clears this register to 00H.
Figure 7-7. Format of Minute Count Register (MIN)
Address: FFF93H After reset: 00H R/W
Symbol
7 6 5 4 3 2 1 0
MIN
0 MIN40
MIN20
MIN10 MIN8 MIN4 MIN2 MIN1
Caution When it reads or writes from/to the register while the counter is in operation (RTCE = 1), follow
the procedures described in 7.4.3 Reading/writing real-time clock.
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Jul 04, 2013