SAM3SD8C Atmel Corporation, SAM3SD8C Datasheet - Page 245

• Manufacturer Part Number: SAM3SD8C
• Manufacturer: Atmel Corporation

14. Real TIme Clock (RTC)
14.1
14.2
Figure 14-1. RTC Block Diagram
14.3
14.3.1
14.3.2
11090A–ATARM–10-Feb-12
11090A–ATARM–10-Feb-12
Description
Block Diagram
Product Dependencies
Slow Clock: SLCK
Power Management
Interrupt
APB
The Real-time Clock (RTC) peripheral is designed for very low power consumption.
It combines a complete time-of-day clock with alarm and a two-hundred-year Gregorian or Per-
sian calendar, complemented by a programmable periodic interrupt. The alarm and calendar
registers are accessed by a 32-bit data bus.
The time and calendar values are coded in binary-coded decimal (BCD) format. The time format
can be 24-hour mode or 12-hour mode with an AM/PM indicator.
Updating time and calendar fields and configuring the alarm fields are performed by a parallel
capture on the 32-bit data bus. An entry control is performed to avoid loading registers with
incompatible BCD format data or with an incompatible date according to the current
month/year/century.
A clock divider calibration circuitry enables to compensate crystal oscillator frequency
inaccuracy.
An RTC output can be programmed to generate several waveforms, including a prescaled clock
derived from 32.768 KHz
The Real-time Clock is continuously clocked at 32768 Hz. The Power Management Controller
has no effect on RTC behavior.
RTC interrupt line is connected on one of the internal sources of the interrupt controller. RTC
interrupt requires the interrupt controller to be programmed first.
Clock Calibration
32768 Divider
User Interface
Control
Entry
Time
Alarm
Date
Interrupt
Control
Generator
Wave
SAM3S8/SD8
SAM3S8/SD8
RTCOUT0
RTCOUT1
RTC Interrupt
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