UM11029
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© NXP Semiconductors N.V. 2017. All rights reserved.
User manual
Rev. 1.0 — 16 June 2017
239 of 515
14.1 How to read this chapter
SCT input multiplexing and DMA input multiplexing is available for all parts.
14.2 Features
•
Configures the inputs to the SCTimer/PWM.
•
Configures the inputs to the DMA triggers.
14.3 Basic configuration
•
In the SYSAHBCLKCTRL register, enable the SCT clock to write to the INPUT MUX
registers. See
.
•
In the SYSAHBCLKCTRL register, enable the DMA clock to write to the DMA
TRIGMUX registers. See
14.4 Pin description
The input multiplexer has no dedicated pins. External pins can be selected as inputs to
the SCT and DMA triggers. Multiplexer inputs from external pins are assigned through the
switch matrix to pins.
14.5 General description
The inputs to the SCTimer/PWM and DMA triggers are multiplexed from multiple input
sources. The sources can be external pins, interrupts, or output signals of other
peripherals.
The input multiplexing makes it possible to design complex event-driven processes
without CPU intervention by connecting peripherals like the SCTimer/PWM and the ADC
or the SCTimer/PWM and the analog comparator.
The DMA can use trigger input multiplexing to sequence DMA transactions without the
use of interrupt service routines.
UM11029
Chapter 14: LPC84x Input multiplexing and DMA trigger
multiplexing (INPUT MUX, DMA TRIGMUX)
Rev. 1.0 — 16 June 2017
User manual
Table 283. INPUT MUX pin description
Pin functions
Peripheral
Input mux reference
SCT_PIN0, SCT_PIN1,
SCT_PIN2, SCT_PIN3
SCT0
