Datasheet

292
SAM4S Series [DATASHEET]
11100F–ATARM–29-Jan-14
32 Hz or 64 Hz can drive, for example, a TN LCD backplane signal while 1 Hz 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 1 Hz periodic high pulse of 15 µs duration that can be used to drive external devices for
power consumption reduction or any other purpose.
PIO lines associated to RTC outputs are automatically selecting these waveforms as soon as RTC_MR corresponding
fields OUT0 and OUT1 differ from 0.
Figure 16-3. Waveform Generation
RTCOUT1
‘0’
1 Hz
32 Hz
64 Hz
512 Hz
toggle_alarm
flag_alarm
pulse
0
1
2
3
4
5
6
7
RTC_MR(OUT1)
RTCOUT0
‘0’
1 Hz
32 Hz
64 Hz
512 Hz
toggle_alarm
flag_alarm
pulse
0
1
2
3
4
5
6
7
RTC_MR(OUT0)
flag_alarm
alarm match
event 1
RTC_SCCR(ALRCLR)
alarm match
event 2
RTC_SCCR(ALRCLR)
toggle_alarm
pulse
Tperiod
Tperiod
Thigh