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 72 of 547
NXP Semiconductors
UM10398
Chapter 7: LPC1100/LPC1100C/LPC1100L series: I/O configuration
• Pseudo open-drain mode for non-I2C pins (see Section 7.1 for part specific details).
7.3 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. If a pin is used as input pin for the ADC, an analog input mode
can be selected.
7.3.1 Pin function
The FUNC bits in the IOCON registers can be set to GPIO (FUNC = 000) or to a
peripheral function. If the pins are GPIO pins, the GPIOnDIR registers determine whether
the pin is configured as an input or output (see Section 12.3.2
). For any peripheral
function, the pin direction is controlled automatically depending on the pin’s functionality.
The GPIOnDIR registers have no effect for peripheral functions.
For open-drain mode, see Section 7.1.
Fig 14. Standard I/O pin configuration
PIN
V
DD
V
DD
ESD
V
SS
ESD
strong
pull-up
strong
pull-down
V
DD
weak
pull-up
weak
pull-down
open-drain enable
output enable
repeater mode
enable
pull-up enable
pull-down enable
data output
data input
analog input
select analog input
002aah159
pin configured
as digital output
driver
pin configured
as digital input
pin configured
as analog input