415
13.2
RTC Registers
13.2.1
64-Hz Counter (R64CNT)
The 64-Hz counter (R64CNT) is an 8-bit read-only register that indicates the states of the RTC
divider circuit, RTC prescaler, and R64CNT between 64 Hz and 1 Hz.
R64CNT is initialized to H'00 by setting the RESET bit in RTC control register 2 (RCR2) or the
ADJ bit in RCR2 to 1.
R64CNT is not initialized by a power-on reset or manual reset, or in standby mode.
Bit 7 is always read as 0.
Bit:
7
6
5
4
3
2
1
0
—
1Hz
2Hz
4Hz
8Hz
16Hz
32Hz
64Hz
Initial value:
0
—
—
—
—
—
—
—
R/W:
R
R
R
R
R
R
R
R
13.2.2
Second Counter (RSECCNT)
The second counter (RSECCNT) is an 8-bit readable/writable register used for setting/counting in
the BCD-coded second section of the RTC. The count operation is performed by a carry for each
second of the 64
-
Hz counter.
The range that can be set is 00
–
59 (decimal). Errant operation will result if any other value is set.
Carry out write processing after halting the count operation with the START bit in RCR2.
RSECCNT is not initialized by a power-on reset or manual reset, or in standby mode.
Bit:
7
6
5
4
3
2
1
0
—
10 seconds
1 second
Initial value:
0
—
—
—
—
—
—
—
R/W:
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Summary of Contents for SH7709S
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