© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
User manual
Rev. 01 — 12 January 2006
71
8.1 Features
•
Every physical GPIO port is accessible via either the group of registers providing an
enhanced features and accelerated port access or the legacy group of registers.
•
Accelerated GPIO functions:
–
GPIO registers are relocated to the ARM local bus to achieve the fastest possible
I/O timing.
–
Mask registers allow treating sets of port bits as a group, leaving other bits
unchanged.
–
All registers are byte and half-word addressable.
–
Entire port value can be written in one instruction.
•
Bit-level set and clear registers allow a single instruction set or clear of any number of
bits in one port.
•
Individual bits can be direction controlled.
•
All I/O default to inputs after reset.
•
Backward compatibility with other earlier devices is maintained with legacy registers
appearing at the original addresses on the APB bus.
8.2 Applications
•
General purpose I/O
•
Driving LEDs or other indicators
•
Controlling off-chip devices
•
Sensing digital inputs
8.3 Pin description
8.4 Register description
LPC2101/02/03 has one 32-bit General Purpose I/O port. A total of 32 input/output pins
are available on PORT0. PORT0 is controlled by the registers shown in
and
Legacy registers shown in
allow backward compatibility with earlier family
devices, using existing code. The functions and relative timing of older GPIO
implementations is preserved.
UM10161
Chapter 8: General Purpose Input/Output ports (GPIO)
Rev. 01 — 12 January 2006
User manual
Table 63:
GPIO pin description
Pin
Type
Description
P0.0-P0.31
Input/
Output
General purpose input/output. The number of GPIOs actually available depends on the
use of alternate functions.