UM11029
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© NXP Semiconductors N.V. 2017. All rights reserved.
User manual
Rev. 1.0 — 16 June 2017
86 of 515
NXP Semiconductors
UM11029
Chapter 8: LPC84x System configuration (SYSCON)
Section 8.6.4 “System oscillator control register”
8.5.3 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 8.6.47 “Power configuration register”
Section 8.6.44 “Start logic 1 interrupt wake-up enable register”
8.5.4 Reset and interrupt control
The peripheral reset control register in the system control register allows to assert and
release individual peripheral resets.
Up to eight external pin interrupts can be assigned to any digital pin in the system control
block (see
Section 8.6.42 “Pin interrupt select registers”
).
8.6 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 shown in
as reserved should not be written to.
Table 125. Register overview: System configuration (base address 0x4004 8000)
Name
Access Offset
Description
Reset value
Section
SYSMEMREMAP
R/W
0x000
System memory remap
0x2
-
-
0x004
Reserved
-
-
SYSPLLCTRL
R/W
0x008
System PLL control
0
SYSPLLSTAT
R
0x00C
System PLL status
0
-
-
0x010
Reserved
-
-
-
- 0x014
Reserved
-
-
-
-
0x018
Reserved
-
-
- -
0x01C
Reserved
-
-
SYSOSCCTRL
R/W 0x020
System
oscillator control
0x000
WDTOSCCTRL
R/W 0x024
Watchdog
oscillator
control
0x000
FROOSCCTRL
R/W
0x028
FRO oscillator control
0x8801
-
- 0x02C
Reserved
-
-
FRODIRECTCLKUEN
R/W
0x030
FRO direct clock source update enable
0
- -
0x034
Reserved
-
-
SYSRSTSTAT
R/W
0x038
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