UM10503
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© NXP B.V. 2012. All rights reserved.
User manual
Rev. 1.3 — 6 July 2012
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10.1 How to read this chapter
The power management controller is identical on all LPC43xx parts.
10.2 General description
The PMC implements the control sequences to enable transitioning between different
power modes and controls the power state of each peripheral. In addition, wake-up from
any of the power-down modes based on hardware events is supported.
Power-down modes can be reached from Active mode only, and transitions between
Power-down modes are not allowed. Power-down modes are entered by a WFI or WFE
instruction. Wake-up is caused by an interrupt or event. The interrupt cause is captured in
the NVIC (
), and events are captured in the Event router (
).
The PMC supports the following Power-down modes: Deep-sleep, Power-down, and
Deep power-down. The wake-up from any of the Power-down modes will always result in
the Active mode.
The LPC43xx supports five power modes in order from highest to lowest power
consumption:
1. Active mode
2. Sleep mode (controlled by the ARM Cortex-M4 core)
3. Power-down modes:
a. Deep-sleep mode (controlled by the ARM Cortex-M4 core)
b. Power-down mode (controlled by the ARM Cortex-M4 core)
c. Deep power-down mode
Remark:
Before the Deep-sleep mode or Power-down mode can be selected, the IRC
must be selected as the clock source for all output clocks through the CGU registers (see
), and all PLLs must be powered down.
10.2.1 Active mode
By default, the LPC43xx is in Active mode, which means that every peripheral can
perform a functional operation at nominal operating conditions.
10.2.2 Sleep mode
In Sleep mode, the CPU clock is shut down to save power; the peripherals can still remain
active and fully functional. The Sleep mode is entered by a WFI or WFE instruction if the
SLEEPDEEP bit in the ARM Cortex-M4 system control register is set to 0.
UM10503
Chapter 10: LPC43xx Power Management Controller (PMC)
Rev. 1.3 — 6 July 2012
User manual