
UM10800
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© NXP Semiconductors N.V. 2016. All rights reserved.
User manual
Rev. 1.2 — 5 October 2016
31 of 487
NXP Semiconductors
UM10800
Chapter 5: LPC82x System configuration (SYSCON)
5.5.3 Configuration of reduced power-modes
The system control block configures analog blocks that can remain running in the reduced
power modes (the BOD and the watchdog oscillator for safe operation) and enables
various interrupts to wake up the chip when the internal clocks are shut down in
Deep-sleep and Power-down modes. For details, see the following registers:
Section 5.6.33 “Power configuration register”
Section 5.6.30 “Start logic 1 interrupt wake-up enable register”
5.5.4 Reset and interrupt control
The peripheral reset control register in the system control register allows to assert and
release individual peripheral resets. See
.
Up to eight external pin interrupts can be assigned to any digital pin in the system control
block (see
Section 5.6.28 “Pin interrupt select registers”
).
5.6 Register description
All system control block registers reside on word address boundaries. Details of the
registers appear in the description of each function.
Reset values describe the content of the registers after the bootloader has executed.
All address offsets not shown in
are reserved and should not be written to.
Table 21.
Register overview: System configuration (base address 0x4004 8000)
Name
Access Offset
Description
Reset value
Reset
value
after boot
Reference
SYSMEMREMAP
R/W
0x000
System memory remap
0x2
PRESETCTRL
R/W
0x004
Peripheral reset control
0x0001 FFFF
SYSPLLCTRL
R/W
0x008
System PLL control
0
SYSPLLSTAT
R
0x00C
System PLL status
0
-
-
0x010
Reserved
-
-
-
- 0x014
Reserved
-
-
SYSOSCCTRL
R/W 0x020
System
oscillator control
0x000
WDTOSCCTRL
R/W 0x024
Watchdog
oscillator
control
0x0A0
IRCCTRL
R/W
0x028
IRC control
0x080
-
- 0x02C
Reserved
-
-
SYSRSTSTAT
R/W
0x030
System reset status register
0
SYSPLLCLKSEL
R/W
0x040
System PLL clock source select
0
SYSPLLCLKUEN
R/W
0x044
System PLL clock source update enable
0
MAINCLKSEL
R/W
0x070
Main clock source select
0
MAINCLKUEN
R/W
0x074
Main clock source update enable
0
SYSAHBCLKDIV
R/W
0x078
System clock divider
1
SYSAHBCLKCTRL
R/W
0x080
System clock control
0xDF
UARTCLKDIV
R/W
0x094
USART clock divider
0