SH7720 Datasheet, PDF (637/1524 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series

Section 17 Realtime Clock (RTC)
17.3.16 RTC Control Register 1 (RCR1)
RCR1 is a register that affects carry flags and alarm flags. It also selects whether to generate
interrupts for each flag.
RCR1 is initialized to H'00 by a power-on reset or 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
Undefined R/W Carry Flag
Status flag that indicates that a carry has
occurred. CF is set to 1 when a count-up to 64-
Hz occurs at the second counter carry or 64-Hz
counter read. A count register value read at this
time cannot be guaranteed; another read is
required.
0: No carry of 64-Hz counter by second counter
or 64-Hz counter
[Clearing condition]
When 0 is written to CF
1: Carry of 64-Hz counter by second counter or
64 Hz counter
[Setting condition]
When the second counter or 64-Hz counter is
read during a carry occurrence by the 64-Hz
counter, or 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.
Rev. 3.00 Jan. 18, 2008 Page 575 of 1458
REJ09B0033-0300