Atmel SAM4S-XPLD Atmel ATSAM4S-XPLD ATSAM4S-XPLD Hoja De Datos

 265

SAM4S [DATASHEET]

11100E–ATARM–24-Jul-13

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 register 
corresponding fields OUT0 and OUT1 differ from 0.

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