Datasheet

Product data sheet Rev. 1.7 — 27 February 2018 25 of 97

NXP Semiconductors

LPC84x

32-bit Arm Cortex-M0+ microcontroller

The Capacitive Touch module measures the change in capacitance of an electrode plate

when an earth-ground connected object (for example, finger) is brought within close

proximity.

8.18 SCTimer/PWM

The SCTimer/PWM can perform basic 16-bit and 32-bit timer/counter functions with match

outputs and external and internal capture inputs. In addition, the SCTimer/PWM can

employ up to eight different programmable states, which can change under the control of

events, to provide complex timing patterns.

The inputs to the SCT are multiplexed between movable functions from the switch matrix

and internal connections such as the ADC threshold compare interrupt, the comparator

output, and the Arm core signals Arm_TXEV and DEBUG_HALTED. The signal on each

SCT input is selected through the INPUT MUX.

All outputs of the SCT are movable functions and are assigned to pins through the switch

matrix. One SCT output can also be selected as one of the ADC conversion triggers.

8.18.1 Features

• Each SCTimer/PWM supports:

– Eight match/capture registers.

– Eight events.

– Eight states.

– Five inputs. The fifth input is hard-wired to a clock source. Each input is

configurable through an input multiplexer to use one of four external pins

(connected through the switch matrix) or one of four internal sources. The

maximum input signal frequency is 25 MHz.

– Six outputs. Connected to pins through the switch matrix.

• Counter/timer features:

– Each SCTimer is configurable as two 16-bit counters or one 32-bit counter.

– Counters can be clocked by the system clock or selected input.

– Configurable as up counters or up-down counters.

– Configurable number of match and capture registers. Up to eight match and

capture registers total.

– Upon match create the following events: interrupt; stop, limit, halt the timer or

change counting direction; toggle outputs.

– Counter value can be loaded into capture register triggered by a match or

input/output toggle.

• PWM features:

– Counters can be used with match registers to toggle outputs and create

time-proportioned PWM signals.

– Up to six single-edge or dual-edge PWM outputs with independent duty cycle and

common PWM cycle length.

• Event creation features: