Hitachi SH7709S Hardware Manual page 444

Bits 6 to 4—Periodic Interrupt Flags (PES2-PES0): Specify the periodic interrupt.
Bit 6: PES2 Bit 5: PES1
0 0
1
1 0
1
Bit 3—RTCEN: Controls the operation of the crystal oscillator for the RTC.
Bit 3: RTCEN Description
0 Crystal oscillator for RTC is halted
1 Crystal oscillator for RTC runs
Bit 2—30 Second Adjustment (ADJ): When 1 is written to the ADJ bit, times of 29 seconds or
less will be rounded to 00 seconds and 30 seconds or more to 1 minute. The divider circuit, RTC
prescaler, and R64CNT will be simultaneously reset. This bit is always read as 0.
Bit 2: ADJ Description
0 Runs normally
1 (Write) 30-second adjustment
Bit 1—Reset (RESET): When 1 is written, initializes the divider circuit (RTC prescaler and
R64CNT). This bit is always read as 0.
Bit 1: RESET Description
0 Runs normally
1 (Write) Divider circuit is reset
Bit 4: PES0 Description
0 No periodic interrupts generated (Initial value)
1 Periodic interrupt generated every 1/256 second
0 Periodic interrupt generated every 1/64 second
1 Periodic interrupt generated every 1/16 second
0 Periodic interrupt generated every 1/4 second
1 Periodic interrupt generated every 1/2 second
0 Periodic interrupt generated every 1 second
1 Periodic interrupt generated every 2 seconds
(Initial value)
(Initial value)
(Initial value)
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