UM10208_2
© NXP B.V. 2007. All rights reserved.
User manual
Rev. 02 — 1 June 2007
149 of 362
NXP Semiconductors
UM10208
Chapter 13: LPC2800 RTC
6.1.6 Alarm Mask Register (AMR - 0x8000 2010)
The Alarm Mask Register (AMR) allows the user to mask any of the alarm registers.
shows the relationship between the bits in the AMR and the alarms. For the
alarm function, every non-masked alarm register must match the corresponding time
counter for an interrupt to be generated. The interrupt is generated only when the counter
comparison first changes from no match to match. The interrupt is removed when a one is
written to the appropriate bit of the Interrupt Location Register (ILR). If all mask bits are
set, then the alarm is disabled.
6.2 Consolidated Time Registers
The values of the Time Counters can optionally be read in a consolidated format which
allows software to read all time counters with only three read operations. The various
registers are packed into 32 bit values as shown in
, and
. The least significant bit of each register is read back at bit 0, 8, 16, and 24.
The Consolidated Time Registers are read only. To write new values to the Time
Counters, the Time Counter addresses should be used.
3
IMDOM
When 1, an increment of the Day of Month value generates an
interrupt.
NA
4
IMDOW
When 1, an increment of the Day of Week value generates an interrupt. NA
5
IMDOY
When 1, an increment of the Day of Year value generates an interrupt.
NA
6
IMMON
When 1, an increment of the Month value generates an interrupt.
NA
7
IMYEAR
When 1, an increment of the Year value generates an interrupt.
NA
31:8
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
NA
Table 157. Counter Increment Interrupt Register (CIIR - address 0x8000 200C)
Bit
Symbol
Description
Reset
value
Table 158. Alarm Mask Register (AMR - address 0x8000 2010)
Bit
Symbol
Description
Reset
value
0
AMRSEC
When 1, the Second value is not compared for the alarm.
NA
1
AMRMIN
When 1, the Minutes value is not compared for the alarm.
NA
2
AMRHOUR When 1, the Hour value is not compared for the alarm.
NA
3
AMRDOM
When 1, the Day of Month value is not compared for the alarm.
NA
4
AMRDOW
When 1, the Day of Week value is not compared for the alarm.
NA
5
AMRDOY
When 1, the Day of Year value is not compared for the alarm.
NA
6
AMRMON
When 1, the Month value is not compared for the alarm.
NA
7
AMRYEAR
When 1, the Year value is not compared for the alarm.
NA