Datasheet

Product data sheet Rev. 1 — 4 June 2012 27 of 69

NXP Semiconductors

LPC3141/3143

Low-cost, low-power ARM926EJ microcontrollers

• After a reset, a register will indicate whether a reset has occurred because of a

watchdog generated reset.

• Watchdog timer can also be used as a normal timer in addition to the watchdog

functionality (output m0).

6.17 Input/Output Configuration module (IOCONFIG)

The General Purpose Input/Output (GPIO) pins can be controlled through the register

interface provided by the IOCONFIG module. Next to several dedicated GPIO pins, most

digital IO pins can also be used as GPIO if they are not required for their normal,

dedicated function.

This module has the following features:

• Provides control for the digital pins that can double as GPIO (next to their normal

function). The pinning list in Table 4

indicates which pins can double as GPIO.

• Each controlled pin can be configured for 4 operational modes:

– Normal operation (i.e. controlled by a function block)

– Driven LOW

– Driven HIGH

– High impedance/input

• A GPIO pin can be observed (read) in any mode.

• The register interface provides ‘set’ and ‘clear’ access methods for choosing the

operational mode.

6.18 10-bit Analog-to-Digital Converter (ADC10B)

This module is a 10-bit successive approximation ADC with an input multiplexer to allow

for multiple analog signals on its input. A common use of this module is to read out

multiple keys on one input from a resistor network.

This module has the following features:

• Four analog input channels, selected by an analog multiplexer.

• Programmable ADC resolution from 2 bit to 10 bit.

• The maximum conversion rate is 400 kSamples/s for 10 bit resolution and

1500 kSamples/s for 2 bit resolution.

• Single and continuous analog-to-digital conversion scan modes.

• Power-down mode.

Fig 7. Block diagram of the Watchdog Timer

002aae086

EVENT ROUTER

WDT

CGU

INTERRUPT

CONTROLLER

FIQ

IRQ

reset

APB