Datasheet

UM10398 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2014. All rights reserved.
User manual Rev. 12.3 — 10 June 2014 105 of 547
8.1 How to read this chapter
Remark: This chapter applies to parts in the following series (see Table 1):
• LPC1100XL
The implementation of the I/O configuration registers varies for different LPC1100XL parts
and packages. Table 105
shows which IOCON registers are used on the different
packages.
8.2 Features
The I/O configuration registers control the electrical characteristics of the pads. The
following features are programmable:
• Pin function.
• Internal pull-up/pull-down resistor or bus keeper function.
• Hysteresis.
• Analog input or digital mode for pads hosting the ADC inputs.
• I
2
C mode for pads hosting the I
2
C-bus function.
• Pseudo open-drain mode for non-I2C pins.
8.3 General description
The IOCON registers control the function (GPIO or peripheral function), the input mode,
and the hysteresis of all PIOn_m pins. In addition, the I
2
C-bus pins can be configured for
different I
2
C-bus modes. An analog input mode can be selected for the input pins to the
ADC.
UM10398
Chapter 8: LPC1100XL series: I/O configuration (IOCONFIG)
Rev. 12.3 — 10 June 2014 User manual