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UM10375
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© NXP B.V. 2011. All rights reserved.
User manual
Rev. 3 — 14 June 2011
38 of 368
NXP Semiconductors
UM10375
Chapter 3: LPC13xx System configuration
•
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
the WDTOSCCTRL = 0001, see
) and all peripheral clocks other than the
timer clock must be disabled in the SYSAHBCLKCTRL register (see
) before
entering Deep-sleep mode.
The watchdog oscillator, if running, contributes an additional current drain in
Deep-sleep mode.
Remark:
Reserved bits in this register must always be written as indicated. This register
must be initialized correctly before entering Deep-sleep mode.
3.5.46 Wake-up configuration register
The bits in this register can be programmed to determine the state the chip must enter
when it is waking up from Deep-sleep mode.
Remark:
Reserved bits in this register must always be written as indicated. This register
must be initialized correctly before entering Deep-sleep mode.
Table 53.
Deep-sleep configuration register (PDSLEEPCFG, address 0x4004 8230) bit
description
Bit
Symbol
Value
Description
Reset
value
2:0
FIXEDVAL
-
Reserved.
Always write these bits as 111.
0
3
BOD_PD
BOD power-down control in Deep-sleep mode, see
.
0
0
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5:4
FIXEDVAL
-
Reserved.
Always write these bits as 11.
0
6
WDTOSC_PD
Watchdog oscillator power control in Deep-sleep
mode, see
.
0
0
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11:7
FIXEDVAL
-
Reserved.
Always write these bits as 11111.
0
31:12
-
0
Reserved
0
Table 54.
Wake-up configuration register (PDAWAKECFG, address 0x4004 8234) bit
description
Bit
Symbol
Value
Description
Reset
value
0
IRCOUT_PD
IRC oscillator output wake-up configuration
0
0
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