RX − 8564 LC

12. Overview of Functions and Description of Registers

12.1. Overview of Functions

1) Clock functions

This function is used to set and read out month, day, hour, date, minute, second, and year (last two digits) data. Any (two-digit) year that is a multiple of 4 is treated as a leap year and calculated automatically as such until the year 2099.

∗For details, see "13.1. Description of Registers".

2)Fixed-cycle interrupt generation function

The fixed-cycle timer interrupt generation function generates an interrupt event periodically at any fixed cycle set between 244.14 ∝ s and 255 minutes.

When an interrupt event is generated, the /INT pin goes to low level ("L") and "1" is set to the TF bit to report that an event has occurred.

Two types of operations can be selected for this function (level interrupt mode and repeated interrupt mode).

∗For details, see "13.2. Fixed-cycle Interrupt Function".

3)Alarm interrupt function

The alarm interrupt generation function generates interrupt events for alarm settings such as date, day, hour, and minute settings.

When an interrupt event occurs, the AF bit value is set to "1" and the /INT pin goes to low level to indicate that an event has occurred.

∗For details, see "13.3. Alarm Interrupt Function".

4)32.768 kHz output function

The 32.768 kHz clock signal (with precision equal to that of the on-chip crystal osillator) can be output (as C-MOS output) via the CLKOUT pin.

If a different frequency is required, 32.768 kHz, 1024 Hz, 32 Hz, or 1 Hz can be selected.

∗For details, see "13.1.9. CLKOUT output register".

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