OM11077 NXP Semiconductors, OM11077 Datasheet - Page 655

• Manufacturer Part Number: OM11077
• Description: MODULE DIMM LPC2478 ARM7
• Manufacturer: NXP Semiconductors

Specifications of OM11077

• Accessory Type: Module Card
• For Use With/related Products: ARM-57TS-LPC2478
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 568-4742

NXP Semiconductors
UM10237_4
User manual
6.4.1 Leap year calculation
6.5 Alarm register group
Table 576. Time Counter relationships and values)
Table 577. Time Counter registers
[1]
The RTC does a simple bit comparison to see if the two lowest order bits of the year
counter are zero. If true, then the RTC considers that year a leap year. The RTC considers
all years evenly divisible by 4 as leap years. This algorithm is accurate from the year 1901
through the year 2099, but fails for the year 2100, which is not a leap year. The only effect
of leap year on the RTC is to alter the length of the month of February for the month, day
of month, and year counters.
The alarm registers are shown in
compared with the time counters. If all the unmasked (See
Register (AMR - 0xE002 4010)” on page
time counters then an interrupt is generated. The interrupt is cleared when a one is written
to bit one of the Interrupt Location Register (ILR[1]).
Counter
Second
Minute
Hour
Day of Month
Day of Week
Day of Year
Month
Year
Name
SEC
MIN
HOUR
DOM
DOW
DOY
MONTH
YEAR
These values are simply incremented at the appropriate intervals and reset at the defined overflow point.
They are not calculated and must be correctly initialized in order to be meaningful.
Size Description
6
6
5
5
3
9
4
12
Size
6
6
5
5
3
9
4
12
Seconds value in the range of 0 to 59
Minutes value in the range of 0 to 59
Hours value in the range of 0 to 23
Day of month value in the range of 1 to 28, 29, 30,
or 31 (depending on the month and whether it is a
leap year).
Day of week value in the range of 0 to 6
Day of year value in the range of 1 to 365 (366 for
leap years)
Month value in the range of 1 to 12
Year value in the range of 0 to 4095
Rev. 04 — 26 August 2009
Enabled by
Clk1 (see
Figure
Second
Minute
Hour
Hour
Hour
Day of Month
Month or day of Year
Chapter 26: LPC24XX Real-Time Clock (RTC) and battery RAM
[1]
[1]
26–134)
Table
26–578. The values in these registers are
653) alarm registers match their corresponding
Minimum value
0
0
0
1
0
1
1
0
[1]
Section 26–6.2.6 “Alarm Mask
R/W
R/W
R/W
Access
R/W
R/W
R/W
R/W
R/W
Maximum value
59
59
23
28, 29, 30 or 31
6
365 or 366 (for leap year)
12
4095
UM10237
© NXP B.V. 2009. All rights reserved.
Address
0xE002 4020
0xE002 4024
0xE002 4028
0xE002 402C
0xE002 4030
0xE002 4034
0xE002 4038
0xE002 403C
655 of 792