UPD78F1502AGK-GAK-AX Datasheet, PDF (369/1031 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcontrollers

78K0R/Lx3
CHAPTER 7 REAL-TIME COUNTER
(5) Sub-count register (RSUBC)
The RSUBC register is a 16-bit register that counts the reference time of 1 second of the real-time counter. It takes
a value of 0000H to 7FFFH and counts 1 second with a clock of 32.768 kHz.
RSUBC can be set by a 16-bit memory manipulation instruction.
Reset signal generation clears this register to 0000H.
Cautions 1. When a correction is made by using the SUBCUD register, the value may become 8000H or
more.
2. This register is also cleared by reset effected by writing the second count register.
3. The value read from this register is not guaranteed if it is read during operation, because a
value that is changing is read.
Figure 7-6. Format of Sub-Count Register (RSUBC)
Address: FFF90H After reset: 0000H R
Symbol
7
6
5
RSUBC
SUBC7
SUBC6
SUBC5
4
SUBC4
3
SUBC3
2
SUBC2
1
SUBC1
0
SUBC0
Address: FFF91H After reset: 0000H R
Symbol
7
6
5
RSUBC
SUBC15
SUBC14
SUBC13
4
SUBC12
3
SUBC11
2
SUBC10
1
SUBC9
0
SUBC8
(6) 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 sub-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 00 to 59 to this register in BCD code.
SEC can be set by an 8-bit memory manipulation instruction.
Reset signal generation clears this register to 00H.
Figure 7-7. Format of Second Count Register (SEC)
Address: FFF92H After reset: 00H R/W
Symbol
7
6
5
SEC
0
SEC40
SEC20
4
SEC10
3
SEC8
2
SEC4
1
SEC2
0
SEC1
R01UH0004EJ0501 Rev.5.01
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Jun 20, 2011