DRAFT
DRAFT DRAFT DR
DRAFT DRAFT DRAFT
D
RAF
DRAFT DRAFT DRA
FT D
RAFT DR
AFT D
DRA
FT DRAFT DRAFT
D
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DRAFT
D
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DRA
UM10601
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2012. All rights reserved.
Preliminary user manual
Rev. 1.0 — 7 November 2012
163 of 313
NXP Semiconductors
UM10601
Chapter 14: LPC800 Self wake-up timer (WKT)
14.6.2 Count register
Do not write to this register while the counting is in progress.
Remark:
In general, reading the timer state is not recommended. There is no mechanism
to ensure that some bits of this register don't change while a read is in progress if the read
happens to coincide with an self wake-up timer clock edge. If you must read this value, it
is recommended to read it twice in succession.
1
ALARMFLAG
Wake-up or alarm timer flag.
-
0
No time-out. The self wake-up timer has not timed out. Writing a 0 to has no effect.
1
Time-out. The self wake-up timer has timed out. This flag generates an interrupt
request which can wake up the part from any reduced power mode including Deep
power-down if the clock source is the low power oscillator. Writing a 1 clears this
status bit.
2
CLEARCTR
Clears the self wake-up timer.
0
0
No effect. Reading this bit always returns 0.
1
Clear the counter. Counting is halted until a new count value is loaded.
31:3
-
Reserved.
-
Table 154. Control register (CTRL, address 0x4000 8000) bit description
Bit
Symbol
Value
Description
Reset
value
Table 155. Counter register (COUNT, address 0x4000 800C) bit description
Bit
Symbol
Description
Reset
value
31:0
VALUE
A write to this register pre-loads start count value into the timer
and starts the count-down sequence.
A read reflects the current value of the timer.
-