212
Philips Semiconductors
Preliminary User Manual
LPC2119/2129/2292/2294
ARM-based Microcontroller
MISCELLANEOUS REGISTER GROUP
Table 176 summarizes the registers located from 0 to 7 of A[6:2]. More detailed descriptions follow.
Interrupt Location (ILR - 0xE0024000)
The Interrupt Location Register is a 2-bit register that specifies which blocks are generating an interrupt (see Table 177). Writing
a one to the appropriate bit clears the corresponding interrupt. Writing a zero has no effect. This allows the programmer to read
this register and write back the same value to clear only the interrupt that is detected by the read.
Clock Tick Counter (CTC - 0xE0024004)
The Clock Tick Counter is read only. It can be reset to zero through the Clock Control Register (CCR). The CTC consists of the
bits of the clock divider counter.
Table 176: Miscellaneous Registers
Address
Name
Size
Description
Access
0xE0024000
ILR
2
RW
0xE0024004
CTC
15
Clock Tick Counter. Value from the clock divider.
RO
0xE0024008
CCR
4
Clock Control Register. Controls the function of the clock divider.
RW
0xE002400C
CIIR
8
RW
0xE0024010
AMR
8
Alarm Mask Register. Controls which of the alarm registers are masked.
RW
0xE0024014
CTIME0
32
Consolidated Time Register 0
RO
0xE0024018
CTIME1
32
Consolidated Time Register 1
RO
0xE002401C
CTIME2
32
Consolidated Time Register 2
RO
Table 177: Interrupt Location Register Bits (ILR - 0xE0024000)
ILR
Function
Description
0
RTCCIF
When one, the Counter Increment Interrupt block generated an interrupt. Writing a one to this bit
location clears the counter increment interrupt.
1
RTCALF
When one, the alarm registers generated an interrupt. Writing a one to this bit location clears the
alarm interrupt.
Table 178: Clock Tick Counter Bits (CTC - 0xE0024004)
CTC
Function
Description
0
Reserved
Reserved, user software should not write ones to reserved bits. The value read from a reserved bit
is not defined.
15:1
Clock Tick
Counter
Prior to the Seconds counter, the CTC counts 32,768 clocks per second. Due to the RTC Prescaler,
these 32,768 time increments may not all be of the same duration. Refer to the Reference Clock
Divider (Prescaler) description for details.