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

The 32-bit value of ALARM0 is continuously compared with the 32-bit CLOCK value, based on the masking set by MASK0.SEL. When a match occurs, the Alarm interrupt flag in the Interrupt Flag Status and Clear register (INTFLAG.ALARM0) is set on the next counter cycle, and the counter is cleared if CTRLA.MATCHCLR is '1'.

Note: This register is write-synchronized: SYNCBUSY.ALARM0 must be checked to ensure the ALARM0 register synchronization is complete.

Name:	ALARM0
Offset:	0x20
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 MASK0.SEL is 6

Bits 25:22 – MONTH[3:0] Month

The alarm month. Months are matched only if MASK0.SEL is greater than 4.

Bits 21:17 – DAY[4:0] Day

The alarm day. Days are matched only if MASK0.SEL is greater than 3.

Bits 16:12 – HOUR[4:0] Hour

The alarm hour. Hours are matched only if MASK0.SEL is greater than 2.

When CTRLA.CLKREP=0, the Hour bit group is in 24-hour format, with values 0-23.

When CTRLA.CLKREP=1, HOUR[3:0] has values 1-12, and HOUR[4] represents AM (0) or PM (1).

Bits 11:6 – MINUTE[5:0] Minute

The alarm minute. Minutes are matched only if MASK0.SEL is greater than 1.

Bits 5:0 – SECOND[5:0] Second

The alarm second. Seconds are matched only if MASK0.SEL is greater than 0.