UM10503
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2012. All rights reserved.
User manual
Rev. 1.3 — 6 July 2012
347 of 1269
NXP Semiconductors
UM10503
Chapter 17: LPC43xx GPIO
The raw interrupt request from each of the two group interrupts is sent to the NVIC, which
can be programmed to treat it as level- or edge-sensitive (see
17.6.5 Recommended practices
The following lists some recommended uses for using the GPIO port registers:
•
For initial setup after Reset or re-initialization, write the PORT registers.
•
To change the state of one pin, write a Byte Pin or Word Pin register.
•
To change the state of multiple pins at a time, write the SET and/or CLR registers.
•
To change the state of multiple pins in a tightly controlled environment like a software
state machine, consider using the NOT register. This can require less write operations
than SET and CLR.
•
To read the state of one pin, read a Byte Pin or Word Pin register.
•
To make a decision based on multiple pins, read and mask a PORT register.
