SAM3SD8C Atmel Corporation, SAM3SD8C Datasheet - Page 250

• Manufacturer Part Number: SAM3SD8C
• Manufacturer: Atmel Corporation

14.4.7
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250
SAM3S8/SD8
SAM3S8/SD8
Waveform Generation
on RTC_MR according to the difference measured between the reference time and those of
RTC_TIMR.
Up to 2 waveforms can be generated at a time from the RTC in order to take advantage of the
RTC inherent prescalers while the RTC is the only powered circuitry (low power mode of opera-
tion, backup mode) or in any active modes. Going into backup or low power operating modes
does not affect the waveform generation outputs.
Both outputs (RTCOUT0, RTCOUT1) can have a source driver selected among 7 possibilities.
RTCOUT0 and RTCOUT1 have independent source selection registers.
For each output:
The first selection choice sticks the associated output at 0. (This is the reset value and it can be
used at anytime to disable the waveform generation.)
Selection choices 1 to 4 respectively select 1Hz, 32Hz, 64Hz and 512Hz.
32Hz or 64Hz can drive, for example, a TN LCD backplane signal while 1Hz can be used to
drive a blinking character like “:” for basic time display (hour, minute) on TN LCDs.
Selection choice 5 provides a toggling signal when the RTC alarm is reached.
Selection choice 6 provides a copy of the alarm flag, so the associated output is set high (logical
1) when an alarm occurs and immediately cleared when software clears the alarm interrupt
source.
Selection choice 7 provides a 1Hz periodic high pulse of 15 µs duration that can be used to drive
external devices for power consumption reduction or any other purpose.
The PIO lines associated to RTCOUT0, RTCOUT1 are automatically selecting these waveforms
as soon as RTC_MR register fields OUT0 and OUT1 differ from 0.
11090A–ATARM–10-Feb-12
11090A–ATARM–10-Feb-12