UM11029
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© NXP Semiconductors N.V. 2017. All rights reserved.
User manual
Rev. 1.0 — 16 June 2017
126 of 515
10.1 How to read this chapter
The switch matrix is identical for all LPC84x parts.
10.2 Features
•
Flexible assignment of digital peripheral functions to pins
•
Enable/disable of analog functions
10.3 Basic configuration
Once configured, no clocks are needed for the switch matrix to function. The system clock
is needed only to write to or read from the pin assignment registers. After the switch matrix
is configured, disable the clock to the switch matrix block in the SYSAHBCLKCTRL
register.
Before activating a peripheral or enabling its interrupt, use the switch matrix to connect the
peripheral to external pins.
The serial wire debug pins SWDIO and SWCLK are enabled by default on pins PIO0_2
and PIO0_3.
Remark:
For the purpose of programming the pin functions through the switch matrix,
every pin except the power and ground pins is identified in a package-independent way by
its GPIO port pin number.
Remark:
The switch matrix is reset by a system reset from the RESET pin as well as all
other resets.
UM11029
Chapter 10: LPC84x Switch matrix (SWM)
Rev. 1.0 — 16 June 2017
User manual