Atmel Xplained Evaluation Board AT32UC3A3-XPLD AT32UC3A3-XPLD Data Sheet
Product codes
AT32UC3A3-XPLD
80
32072H–AVR32–10/2012
AT32UC3A3
8.
Real Time Counter (RTC)
Rev: 2.4.0.1
8.1
Features
•
32-bit real-time counter with 16-bit prescaler
•
Clocked from RC oscillator or 32KHz oscillator
•
Long delays
– Max timeout 272years
•
High resolution: Max count frequency 16KHz
•
Extremely low power consumption
•
Available in all sleep modes except Static
•
Interrupt on wrap
8.2
Overview
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 system RC oscillator or the 32 KHz crystal oscillator. Any tapping of the prescaler can be
selected as clock source for the RTC, enabling both high resolution and long timeouts. The pres-
caler cannot be written directly, but can be cleared by the user.
surement of real-time sequences. The RTC is fed from a 16-bit prescaler, which is clocked from
the system RC oscillator or the 32 KHz crystal oscillator. Any tapping of the prescaler can be
selected as clock source for the RTC, enabling both high resolution and long timeouts. The pres-
caler cannot be written directly, but can be cleared by the user.
The RTC can generate an interrupt when the counter wraps around the value stored in the top
register (TOP), producing accurate periodic interrupts.
register (TOP), producing accurate periodic interrupts.
8.3
Block Diagram
Figure 8-1.
Real Time Counter Block Diagram
8.4
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
below.
16-bit Prescaler
RCSYS
32-bit counter
VAL
TOP
TOPI
IRQ
CLK_32
CTRL
EN
CLK32
PSEL
1
0