AT32AP7002_1 Datasheet, PDF (117/896 Pages) ATMEL Corporation – AVR32 32-bit Microcontroller

AT32AP7002
11. Real Time Counter (RTC)
11.1 Features
Rev: 1.0.1.1
11.2 Description
• 32-bit real-time counter with 16-bit prescaler
• Clocked from 32 kHz oscillator
• High resolution: Max count frequency 16KHz
• Long delays
– Max timeout 272 years
• Extremely low power consumption
• Available in all sleep modes except Deepdown
• Optional wrap at max value
• Interrupt on wrap
The Real Time Counter (RTC) enables periodic interrupts at long intervals, or accurate mea-
surement of real-time sequences. The RTC is fed from a 16-bit prescaler, which is clocked from
the 32 kHz oscillator. Any tapping of the prescaler can be selected as clock source for the RTC,
enabling both high resolution and long timeouts. The prescaler cannot be written directly, but
can be cleared by the user.
The RTC can generate an interrupt when the counter wraps around the top value of
0xFFFFFFFF. Optionally, the RTC can wrap at a lower value, producing accurate periodic
interrupts.
11.3 Block Diagram
Figure 11-1. Real Time Counter module block diagram
RTC_TOP
32 KHz
16-bit Prescaler
32-bit counter
TOPI
IRQ
11.4 Product Dependencies
11.4.1 I/O Lines
None.
RTC_VAL
32054F–AVR32–09/09
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