UM10503
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© NXP B.V. 2015. All rights reserved.
User manual
Rev. 2.1 — 10 December 2015
475 of 1441
NXP Semiconductors
UM10503
Chapter 19: LPC43xx/LPC43Sxx 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
19.6.5 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.