
UM10800
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© NXP Semiconductors N.V. 2016. All rights reserved.
User manual
Rev. 1.2 — 5 October 2016
156 of 487
11.1 How to read this chapter
SCT input multiplexing and DMA input multiplexing is available for all parts.
11.2 Features
•
Configures the inputs to the SCTimer/PWM.
•
Configures the inputs to the DMA triggers.
11.3 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
.
11.4 Pin description
The input multiplexer has no dedicated pins. However, external pins can be selected as
inputs to the SCT input multiplexer. Multiplexer inputs from external pins are assigned
through the switch matrix to pins.
11.5 General description
The inputs to the four SCTs, to the DMA trigger, to the eight pin interrupts, and to the
frequency measure block are multiplexed to 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 SCT and the ADC or the SCT
and the analog comparator.
The DMA can use trigger input multiplexing to sequence DMA transactions without the
use of interrupt service routines.
UM10800
Chapter 11: LPC82x Input multiplexing and DMA trigger
multiplexing (INPUT MUX, DMA TRIGMUX)
Rev. 1.2 — 5 October 2016
User manual
Table 142. INPUT MUX pin description
Pin functions
Peripheral
Input mux reference
SCT_PIN0, SCT_PIN1,
SCT_PIN2, SCT_PIN3
SCT0