Datasheet

LPC11U2X All information provided in this document is subject to legal disclaimers. © NXP B.V. 2014. All rights reserved.
Product data sheet Rev. 2.3 — 27 March 2014 22 of 74
NXP Semiconductors
LPC11U2x
32-bit ARM Cortex-M0 microcontroller
7.17 Clocking and power control
7.17.1 Integrated oscillators
The LPC11U2x include three independent oscillators: the system oscillator, the Internal
RC oscillator (IRC), and the watchdog oscillator. Each oscillator can be used for more
than one purpose as required in a particular application.
Following reset, the LPC11U2x operates from the internal RC oscillator until software
switches to a different clock source. The IRC allows the system to operate without any
external crystal and the bootloader code to operate at a known frequency.
See Figure 7
for an overview of the LPC11U2x clock generation.