SH7706 Datasheet, PDF (400/749 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH™ RISC engine Family/SH7700 Series

Section 13 Realtime Clock (RTC)
13.3.15 RTC Control Register 1 (RCR1)
RTC control register 1 (RCR1) 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 an 8-bit read/write register. Bits CIE, AIE, and AF are initialized by a power-on reset or
manual reset. After a power-on reset or manual reset, however, the CF flag 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
—
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
Rev. 5.00 May 29, 2006 page 352 of 698
REJ09B0146-0500