Datasheet
LPC11U3X All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2014. All rights reserved.
Product data sheet Rev. 2.2 — 11 March 2014  19 of 77
NXP Semiconductors
LPC11U3x
32-bit ARM Cortex-M0 microcontroller
• Four programmable interrupt priority levels, with hardware priority level masking.
• Software interrupt generation.
7.6.2 Interrupt sources
Each peripheral device has one interrupt line connected to the NVIC but can have several 
interrupt flags. Individual interrupt flags can also represent more than one interrupt 
source.
7.7 IOCON block
The IOCON block allows selected pins of the microcontroller to have more than one 
function. Configuration registers control the multiplexers to allow connection between the 
pin and the on-chip peripherals.
Connect peripherals to the appropriate pins before activating the peripheral and before 
enabling any related interrupt. Activity of any enabled peripheral function that is not 
mapped to a related pin is treated as undefined.
7.7.1 Features
• Programmable pull-up, pull-down, or repeater mode.
• All GPIO pins (except PIO0_4 and PIO0_5) are pulled up to 3.3 V (V
DD
 = 3.3 V) if their 
pull-up resistor is enabled.
• Programmable pseudo open-drain mode.
• Programmable 10 ns glitch filter on pins PIO0_22, PIO0_23, and PIO0_11 to 
PIO0_16. The glitch filter is turned on by default.
• Programmable hysteresis.
• Programmable input inverter.
7.8 General-Purpose Input/Output GPIO
The GPIO registers control device pin functions that are not connected to a specific 
peripheral function. Pins can be dynamically configured as inputs or outputs. Multiple 
outputs can be set or cleared in one write operation. 
LPC11U3x use accelerated GPIO functions:
• GPIO registers are a dedicated AHB peripheral so that the fastest possible I/O timing 
can be achieved.
• Entire port value can be written in one instruction.
Any GPIO pin providing a digital function can be programmed to generate an interrupt on 
a level, a rising or falling edge, or both. 
The GPIO block consists of three parts:
1. The GPIO ports.
2. The GPIO pin interrupt block to control eight GPIO pins selected as pin interrupts.
3. Two GPIO group interrupt blocks to control two combined interrupts from all GPIO 
pins.










