Intel PXA27 Series Design Manual page 265

D.21 Real-Time Clock (RTC)
The real-time clock (RTC) controller of the PXA27x processor is similar to that of the PXA25x
processor except for these changes:
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Features added to the PXA27x processor real time clock:
— Timer Section
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— Wristwatch Section
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hours, minutes, seconds, day of week, week of month, day of month, month, and year
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seconds, day of week, week of month, day of month, month, and year
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— Stopwatch Section
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in terms of hours, minutes, seconds, and hundredths of a second
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minutes, seconds, and hundredths of a second
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— Periodic Interrupt Section
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Changes to the registers within the PXA25x processor operating system timers were required
to support the new features of the PXA27x processor operating system timers:
— The RTSR register has 12 new alarm and alarm enable bits.
— The following registers have been created:
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Intel PXA27x Processor Family Design Guide
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Intel PXA27x Processor and Intel
Resolution is now required to be one second
User-programmable, free-running counter containing time of the day in terms of
User-programmable alarm registers to generate alarms in terms of hours, minutes,
Resolution of one second
Programmable counter register that contains the time elapsed between two events
Two user-programmable alarm registers to generate alarms in terms of hours,
th
Resolution of one 100 of a second
Programmable alarm register to generate periodic interrupts at regular intervals
Resolution of one millisecond
Two Wristwatch Day Alarm registers
Two Wristwatch Year Alarm registers
Two Stopwatch Alarm registers
A single Periodic Interrupt Alarm register
A single RTC Day Counter register
A single RTC Year Counter register
A single Stopwatch Counter register
A single Periodic Interrupt Counter register
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PXA25x Processor Differences
D-11