UM10429
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© NXP B.V. 2010. All rights reserved.
User manual
Rev. 1 — 20 October 2010
26 of 258
NXP Semiconductors
UM10429
Chapter 3: LPC1102 System configuration
3.5.27 Deep-sleep mode configuration register
This register controls the behavior of the WatchDog (WD) oscillator and the BOD circuit
when the device enters Deep-sleep mode.
This register
must be initialized at least once before entering Deep-sleep mode
with
one of the four values shown in
:
Remark:
Failure to initialize and program this register correctly may result in undefined
behavior of the microcontroller. The values listed in
are the only values allowed
for PDSLEEPCFG register.
To select the appropriate power configuration for Deep-sleep mode, consider the
following:
•
BOD: Leaving the BOD circuit enabled will protect the part from a low voltage event
occurring while the part is in Deep-sleep mode. However, the BOD circuit causes an
additional current drain in Deep-sleep mode.
•
WD oscillator: The watchdog oscillator can be left running in Deep-sleep mode to
provide a clock for the watchdog timer or a general purpose timer if they are needed
for timing a wake-up event (see
for details). In this case, the watchdog
oscillator analog output frequency must be set to its lowest value (bits FREQSEL in
8
SRPIO0_8
Start signal status for start logic input PIO0_8
n/a
0
No start signal received
1
Start signal pending
9
SRPIO0_9
Start signal status for start logic input PIO0_9
n/a
0
No start signal received
1
Start signal pending
10
SRPIO0_10
Start signal status for start logic input PIO0_10
n/a
0
No start signal received
1
Start signal pending
11
SRPIO0_11
Start signal status for start logic input PIO0_11
n/a
0
No start signal received
1
Start signal pending
12
SRPIO1_0
Start signal status for start logic input PIO1_0
n/a
0
No start signal received
1
Start signal pending
31:13
-
-
Reserved
n/a
Table 31.
Start logic status register 0 (STARTSRP0, address 0x4004 820C) bit description
Bit
Symbol
Value
Description
Reset
value
Table 32.
Allowed values for PDSLEEPCFG register
Configuration
WD oscillator on
WD oscillator off
BOD on
PDSLEEPCFG = 0x0000 18B7 PDSLEEPCFG = 0x0000 18F7
BOD off
PDSLEEPCFG = 0x0000 18BF PDSLEEPCFG = 0x0000 18FF