HD6417706 Datasheet, PDF (384/709 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer Super RISC engine Family/SH7700 Series

13.3.15 RTC Control Register 1 (RCR1)
The RTC control register 1 (RCR1) is an 8-bit read/write register that affects carry flags and alarm
flags. It also selects whether to generate interrupts for each flag. Because flags are sometimes set
after an operand read, do not use this register in read-modify-write processing.
RCR1 is initialized to H'00 by a power-on reset. In a manual reset, all bits are initialized to 0
except for the CF flag, which is undefined. When using the CF flag, it must be initialized
beforehand. This register is not initialized in standby mode.
Bit
Bit Name Initial Value R/W Description
7
CF
0
R/W Carry Flag
Status flag that indicates that a carry has occurred. CF
is set to 1 when a count-up to R64CNT or RSECCNT
occurs. A count register value read at this time cannot
be guaranteed; another read is required.
0: No count up of R64CNT or RSECCNT.
[Clearing condition]
When 0 is written to CF
1: Count up of R64CNT or RSECCNT.
[Setting condition]
When 1 is written to CF
6, 5
—
All 0
R Reserved
These bits are always read as 0. The write value should
always be 0.
4
CIE
0
R/W Carry Interrupt Enable Flag
When the carry flag (CF) is set to 1, the CIE bit enables
interrupts.
0: A carry interrupt is not generated when the CF flag is
set to 1
1: A carry interrupt is generated when the CF flag is set
to 1
3
AIE
0
R/W Alarm Interrupt Enable Flag
When the alarm flag (AF) is set to 1, the AIE bit allows
interrupts.
0: An alarm interrupt is not generated when the AF flag
is set to 1
1: An alarm interrupt is generated when the AF flag is
set to 1
Rev. 4.00, 03/04, page 338 of 660