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UM10375
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© NXP B.V. 2011. All rights reserved.
User manual
Rev. 3 — 14 June 2011
53 of 368
NXP Semiconductors
UM10375
Chapter 4: LPC13xx Power Management Unit (PMU)
4.2.2 General purpose registers 0 to 3
The general purpose registers retain data through the Deep power-down mode when
power is still applied to the V
DD
pin but the chip has entered Deep power-down mode.
Only a “cold” boot when all power has been completely removed from the chip will reset
the general purpose registers.
4.2.3 General purpose register 4
The general purpose register 4 retains data through the Deep power-down mode when
power is still applied to the V
DD
pin but the chip has entered Deep power-down mode.
Only a “cold” boot, when all power has been completely removed from the chip, will reset
the general purpose registers.
The hysteresis of the WAKEUP pin in Deep power-down mode can be controlled by bit 10
of this register.
Remark:
If there is a possibility that the external voltage applied on pin V
DD
drops below
2.2 V during Deep power-down, the hysteresis of the WAKEUP input pin has to be
disabled in this register before entering Deep power-down mode in order for the chip to
wake up.
4.3 Functional description
See
for details on power management and the Deep power-down mode.
11
DPDFLAG
Deep power-down flag
0x0
0
Read: Deep power-down mode
not
entered.
Write: No effect.
0x0
1
Read: Deep power-down mode entered.
Write: Clear the Deep power-down flag.
0x0
31:12
-
-
Reserved. Do not write ones to this bit.
0x0
Table 61.
Power control register (PCON, address 0x4003 8000) bit description
…continued
Bit
Symbol
Value
Description
Reset
value
Table 62.
General purpose registers 0 to 3 (GPREG0 - GPREG3, address 0x4003 8004 to
0x4003 8010) bit description
Bit
Symbol
Description
Reset
value
31:0
GPDATA
Data retained during Deep power-down mode.
0x0
Table 63.
General purpose register 4 (GPREG4, address 0x4003 8014) bit description
Bit
Symbol
Value
Description
Reset
value
9:0
-
-
Reserved. Do not write ones to this bit.
0x0
10
WAKEUPHYS
WAKEUP pin hysteresis enable
0x0
0
Hysteresis for WAKUP pin disabled.
1
Hysteresis for WAKEUP pin enabled.
31:11
GPDATA
Data retained during Deep power-down mode.
0x0