24.9.11 Alarm Value in Clock/Calendar mode (CTRLA.MODE=2)

The 32-bit value of ALARM is continuously compared with the 32-bit CLOCK value, based on the masking set by MASK.SEL. When a match occurs, the Alarm n interrupt flag in the Interrupt Flag Status and Clear register (INTFLAG.ALARM) is set on the next counter cycle, and the counter is cleared if CTRLA.MATCHCLR is '1'.

Table 24-47. Register Bit Attribute Legend
Symbol	Description	Symbol	Description	Symbol	Description
R	Readable bit	HC	Cleared by Hardware	(Grey cell)	Unimplemented
W	Writable bit	HS	Set by Hardware	X	Bit is unknown at Reset
K	Write to clear	S	Software settable bit	—	—

Name:	ALARM
Offset:	0x20 + n*0x08 [n=0..1]
Reset:	0x00000000
Property:	PAC Write-Protection, Write-Synchronized


Bit	31	30	29	28	27	26	25	24
	YEAR[5:0]						MONTH[3:2]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	23	22	21	20	19	18	17	16
	MONTH[1:0]		DAY[4:0]					HOUR[4]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	15	14	13	12	11	10	9	8
	HOUR[3:0]				MINUTE[5:2]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	7	6	5	4	3	2	1	0
	MINUTE[1:0]		SECOND[5:0]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0

Bits 31:26 – YEAR[5:0] Year

The alarm year. Years are only matched if MASK.SEL is 6

Bits 25:22 – MONTH[3:0] Month

The alarm month. Months are matched only if MASK.SEL is greater than 4.

Bits 21:17 – DAY[4:0] Day

The alarm day. Days are matched only if MASK.SEL is greater than 3.

Bits 16:12 – HOUR[4:0] Hour

The alarm hour. Hours are matched only if MASK.SEL is greater than 2.

Bits 11:6 – MINUTE[5:0] Minute

The alarm minute. Minutes are matched only if MASK.SEL is greater than 1.

Bits 5:0 – SECOND[5:0] Second

The alarm second. Seconds are matched only if MASK.SEL is greater than 0.