SAM3XA RTC

Real-time Clock (RTC) User Interface

Registers

Register Mapping

Address	Register	Name	Access	Reset
0x400E1A60	Control Register	RTC_CR	read-write	0x00000000
0x400E1A64	Mode Register	RTC_MR	read-write	0x00000000
0x400E1A68	Time Register	RTC_TIMR	read-write	0x00000000
0x400E1A6C	Calendar Register	RTC_CALR	read-write	0x01210720
0x400E1A70	Time Alarm Register	RTC_TIMALR	read-write	0x00000000
0x400E1A74	Calendar Alarm Register	RTC_CALALR	read-write	0x01010000
0x400E1A78	Status Register	RTC_SR	read-only	0x00000000
0x400E1A7C	Status Clear Command Register	RTC_SCCR	write-only	-
0x400E1A80	Interrupt Enable Register	RTC_IER	write-only	-
0x400E1A84	Interrupt Disable Register	RTC_IDR	write-only	-
0x400E1A88	Interrupt Mask Register	RTC_IMR	read-only	0x00000000
0x400E1A8C	Valid Entry Register	RTC_VER	read-only	0x00000000
0x400E1B44	Write Protect Mode Register	RTC_WPMR	read-write	0x00000000

Register Fields

RTC Control Register

Name: RTC_CR

Access: read-write

Address: 0x400E1A60

31	30	29	28	27	26	25	24
-	-	-	-	-	-	-	-
23	22	21	20	19	18	17	16
-	-	-	-	-	-	CALEVSEL
15	14	13	12	11	10	9	8
-	-	-	-	-	-	TIMEVSEL
7	6	5	4	3	2	1	0
-	-	-	-	-	-	UPDCAL	UPDTIM

• UPDTIM: Update Request Time Register

  Value	Name	Description
  0	-	No effect.
  1	-	Stops the RTC time counting.

• UPDCAL: Update Request Calendar Register

  Value	Name	Description
  0	-	No effect.
  1	-	Stops the RTC calendar counting.

• TIMEVSEL: Time Event Selection

  Value	Name	Description
  0x0	MINUTE	Minute change
  0x1	HOUR	Hour change
  0x2	MIDNIGHT	Every day at midnight
  0x3	NOON	Every day at noon

• CALEVSEL: Calendar Event Selection

  Value	Name	Description
  0x0	WEEK	Week change (every Monday at time 00:00:00)
  0x1	MONTH	Month change (every 01 of each month at time 00:00:00)
  0x2	YEAR	Year change (every January 1 at time 00:00:00)

RTC Mode Register

Name: RTC_MR

Access: read-write

Address: 0x400E1A64

31	30	29	28	27	26	25	24
-	-	-	-	-	-	-	-
23	22	21	20	19	18	17	16
-	-	-	-	-	-	-	-
15	14	13	12	11	10	9	8
-	-	-	-	-	-	-	-
7	6	5	4	3	2	1	0
-	-	-	-	-	-	-	HRMOD

• HRMOD: 12-/24-hour Mode

  Value	Name	Description
  0	-	24-hour mode is selected.
  1	-	12-hour mode is selected.

RTC Time Register

Name: RTC_TIMR

Access: read-write

Address: 0x400E1A68

31	30	29	28	27	26	25	24
-	-	-	-	-	-	-	-
23	22	21	20	19	18	17	16
-	AMPM	HOUR
15	14	13	12	11	10	9	8
-	MIN
7	6	5	4	3	2	1	0
-	SEC

• SEC: Current Second

-

• MIN: Current Minute

-

• HOUR: Current Hour

-

• AMPM: Ante Meridiem Post Meridiem Indicator

  Value	Name	Description
  0	-	AM.
  1	-	PM.

RTC Calendar Register

Name: RTC_CALR

Access: read-write

Address: 0x400E1A6C

31	30	29	28	27	26	25	24
-	-	DATE
23	22	21	20	19	18	17	16
DAY			MONTH
15	14	13	12	11	10	9	8
YEAR
7	6	5	4	3	2	1	0
-	CENT

• CENT: Current Century

-

• YEAR: Current Year

-

• MONTH: Current Month

-

• DAY: Current Day in Current Week

-

• DATE: Current Day in Current Month

-

RTC Time Alarm Register

Name: RTC_TIMALR

Access: read-write

Address: 0x400E1A70

31	30	29	28	27	26	25	24
-	-	-	-	-	-	-	-
23	22	21	20	19	18	17	16
HOUREN	AMPM	HOUR
15	14	13	12	11	10	9	8
MINEN	MIN
7	6	5	4	3	2	1	0
SECEN	SEC

• SEC: Second Alarm

-

• SECEN: Second Alarm Enable

  Value	Name	Description
  0	-	The second-matching alarm is disabled.
  1	-	The second-matching alarm is enabled.

• MIN: Minute Alarm

-

• MINEN: Minute Alarm Enable

  Value	Name	Description
  0	-	The minute-matching alarm is disabled.
  1	-	The minute-matching alarm is enabled.

• HOUR: Hour Alarm

-

• AMPM: AM/PM Indicator

-

• HOUREN: Hour Alarm Enable

  Value	Name	Description
  0	-	The hour-matching alarm is disabled.
  1	-	The hour-matching alarm is enabled.

RTC Calendar Alarm Register

Name: RTC_CALALR

Access: read-write

Address: 0x400E1A74

31	30	29	28	27	26	25	24
DATEEN	-	DATE
23	22	21	20	19	18	17	16
MTHEN	-	-	MONTH
15	14	13	12	11	10	9	8
-	-	-	-	-	-	-	-
7	6	5	4	3	2	1	0
-	-	-	-	-	-	-	-

• MONTH: Month Alarm

-

• MTHEN: Month Alarm Enable

  Value	Name	Description
  0	-	The month-matching alarm is disabled.
  1	-	The month-matching alarm is enabled.

• DATE: Date Alarm

-

• DATEEN: Date Alarm Enable

  Value	Name	Description
  0	-	The date-matching alarm is disabled.
  1	-	The date-matching alarm is enabled.

RTC Status Register

Name: RTC_SR

Access: read-only

Address: 0x400E1A78

31	30	29	28	27	26	25	24
-	-	-	-	-	-	-	-
23	22	21	20	19	18	17	16
-	-	-	-	-	-	-	-
15	14	13	12	11	10	9	8
-	-	-	-	-	-	-	-
7	6	5	4	3	2	1	0
-	-	-	CALEV	TIMEV	SEC	ALARM	ACKUPD

• ACKUPD: Acknowledge for Update

  Value	Name	Description
  0	-	Time and calendar registers cannot be updated.
  1	-	Time and calendar registers can be updated.

• ALARM: Alarm Flag

  Value	Name	Description
  0	-	No alarm matching condition occurred.
  1	-	An alarm matching condition has occurred.

• SEC: Second Event

  Value	Name	Description
  0	-	No second event has occurred since the last clear.
  1	-	At least one second event has occurred since the last clear.

• TIMEV: Time Event

  Value	Name	Description
  0	-	No time event has occurred since the last clear.
  1	-	At least one time event has occurred since the last clear.

• CALEV: Calendar Event

  Value	Name	Description
  0	-	No calendar event has occurred since the last clear.
  1	-	At least one calendar event has occurred since the last clear.

RTC Status Clear Command Register

Name: RTC_SCCR

Access: write-only

Address: 0x400E1A7C

31	30	29	28	27	26	25	24
-	-	-	-	-	-	-	-
23	22	21	20	19	18	17	16
-	-	-	-	-	-	-	-
15	14	13	12	11	10	9	8
-	-	-	-	-	-	-	-
7	6	5	4	3	2	1	0
-	-	-	CALCLR	TIMCLR	SECCLR	ALRCLR	ACKCLR

• ACKCLR: Acknowledge Clear

  Value	Name	Description
  0	-	No effect.
  1	-	Clears corresponding status flag in the Status Register (RTC_SR).

• ALRCLR: Alarm Clear

  Value	Name	Description
  0	-	No effect.
  1	-	Clears corresponding status flag in the Status Register (RTC_SR).

• SECCLR: Second Clear

  Value	Name	Description
  0	-	No effect.
  1	-	Clears corresponding status flag in the Status Register (RTC_SR).

• TIMCLR: Time Clear

  Value	Name	Description
  0	-	No effect.
  1	-	Clears corresponding status flag in the Status Register (RTC_SR).

• CALCLR: Calendar Clear

  Value	Name	Description
  0	-	No effect.
  1	-	Clears corresponding status flag in the Status Register (RTC_SR).

RTC Interrupt Enable Register

Name: RTC_IER

Access: write-only

Address: 0x400E1A80

31	30	29	28	27	26	25	24
-	-	-	-	-	-	-	-
23	22	21	20	19	18	17	16
-	-	-	-	-	-	-	-
15	14	13	12	11	10	9	8
-	-	-	-	-	-	-	-
7	6	5	4	3	2	1	0
-	-	-	CALEN	TIMEN	SECEN	ALREN	ACKEN

• ACKEN: Acknowledge Update Interrupt Enable

  Value	Name	Description
  0	-	No effect.
  1	-	The acknowledge for update interrupt is enabled.

• ALREN: Alarm Interrupt Enable

  Value	Name	Description
  0	-	No effect.
  1	-	The alarm interrupt is enabled.

• SECEN: Second Event Interrupt Enable

  Value	Name	Description
  0	-	No effect.
  1	-	The second periodic interrupt is enabled.

• TIMEN: Time Event Interrupt Enable

  Value	Name	Description
  0	-	No effect.
  1	-	The selected time event interrupt is enabled.

• CALEN: Calendar Event Interrupt Enable

  Value	Name	Description
  0	-	No effect.

RTC Interrupt Disable Register

Name: RTC_IDR

Access: write-only

Address: 0x400E1A84

31	30	29	28	27	26	25	24
-	-	-	-	-	-	-	-
23	22	21	20	19	18	17	16
-	-	-	-	-	-	-	-
15	14	13	12	11	10	9	8
-	-	-	-	-	-	-	-
7	6	5	4	3	2	1	0
-	-	-	CALDIS	TIMDIS	SECDIS	ALRDIS	ACKDIS

• ACKDIS: Acknowledge Update Interrupt Disable

  Value	Name	Description
  0	-	No effect.
  1	-	The acknowledge for update interrupt is disabled.

• ALRDIS: Alarm Interrupt Disable

  Value	Name	Description
  0	-	No effect.
  1	-	The alarm interrupt is disabled.

• SECDIS: Second Event Interrupt Disable

  Value	Name	Description
  0	-	No effect.
  1	-	The second periodic interrupt is disabled.

• TIMDIS: Time Event Interrupt Disable

  Value	Name	Description
  0	-	No effect.
  1	-	The selected time event interrupt is disabled.

• CALDIS: Calendar Event Interrupt Disable

  Value	Name	Description
  0	-	No effect.
  1	-	The selected calendar event interrupt is disabled.

RTC Interrupt Mask Register

Name: RTC_IMR

Access: read-only

Address: 0x400E1A88

31	30	29	28	27	26	25	24
-	-	-	-	-	-	-	-
23	22	21	20	19	18	17	16
-	-	-	-	-	-	-	-
15	14	13	12	11	10	9	8
-	-	-	-	-	-	-	-
7	6	5	4	3	2	1	0
-	-	-	CAL	TIM	SEC	ALR	ACK

• ACK: Acknowledge Update Interrupt Mask

  Value	Name	Description
  0	-	The acknowledge for update interrupt is disabled.
  1	-	The acknowledge for update interrupt is enabled.

• ALR: Alarm Interrupt Mask

  Value	Name	Description
  0	-	The alarm interrupt is disabled.
  1	-	The alarm interrupt is enabled.

• SEC: Second Event Interrupt Mask

  Value	Name	Description
  0	-	The second periodic interrupt is disabled.
  1	-	The second periodic interrupt is enabled.

• TIM: Time Event Interrupt Mask

  Value	Name	Description
  0	-	The selected time event interrupt is disabled.
  1	-	The selected time event interrupt is enabled.

• CAL: Calendar Event Interrupt Mask

  Value	Name	Description
  0	-	The selected calendar event interrupt is disabled.
  1	-	The selected calendar event interrupt is enabled.

RTC Valid Entry Register

Name: RTC_VER

Access: read-only

Address: 0x400E1A8C

31	30	29	28	27	26	25	24
-	-	-	-	-	-	-	-
23	22	21	20	19	18	17	16
-	-	-	-	-	-	-	-
15	14	13	12	11	10	9	8
-	-	-	-	-	-	-	-
7	6	5	4	3	2	1	0
-	-	-	-	NVCALALR	NVTIMALR	NVCAL	NVTIM

• NVTIM: Non-valid Time

  Value	Name	Description
  0	-	No invalid data has been detected in RTC_TIMR (Time Register).
  1	-	RTC_TIMR has contained invalid data since it was last programmed.

• NVCAL: Non-valid Calendar

  Value	Name	Description
  0	-	No invalid data has been detected in RTC_CALR (Calendar Register).
  1	-	RTC_CALR has contained invalid data since it was last programmed.

• NVTIMALR: Non-valid Time Alarm

  Value	Name	Description
  0	-	No invalid data has been detected in RTC_TIMALR (Time Alarm Register).
  1	-	RTC_TIMALR has contained invalid data since it was last programmed.

• NVCALALR: Non-valid Calendar Alarm

  Value	Name	Description
  0	-	No invalid data has been detected in RTC_CALALR (Calendar Alarm Register).
  1	-	RTC_CALALR has contained invalid data since it was last programmed.

RTC Write Protect Mode Register

Name: RTC_WPMR

Access: read-write

Address: 0x400E1B44

31	30	29	28	27	26	25	24
WPKEY
23	22	21	20	19	18	17	16
WPKEY
15	14	13	12	11	10	9	8
WPKEY
7	6	5	4	3	2	1	0
-	-	-	-	-	-	-	WPEN

• WPEN: Write Protect Enable

  Value	Name	Description
  0	-	Disables the Write Protect if WPKEY corresponds to 0x525443 ("RTC" in ASCII).
  1	-	Enables the Write Protect if WPKEY corresponds to 0x525443 ("RTC" in ASCII).

• WPKEY

-