Atmel SAM9X25, Manual

Page: 121 / 1145

121
11054A–ATARM–27-Jul-11
SAM9X25
121
11054A–ATARM–27-Jul-11
SAM9X25
15. Real-time Clock (RTC)
15.1 Description
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 calen-
dar, 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.
15.2 Embedded Characteristics
• Low Power Consumption
• Full Asynchronous Design
• Two Hundred Year Gregorian Calendar
• Programmable Periodic Interrupt
• Time, Date and Alarm 32-bit Parallel Load
15.3 Block Diagram
Figure 15-1. RTC Block Diagram
Bus Interface
32768 Divider Time Slow Clock: SLCK
Bus Interface
Date
RTC Interrupt
Entry
Control
Interrupt
Control