Chapter 26: Lpc29Xx Analog-To-Digital Converter (Adc); How To Read This Chapter; Adc Functional Description - NXP Semiconductors LPC29 Series User Manual

1. How to read this chapter

The contents of this chapter apply to all LPC29xx parts. ADC0 is available in
LPC2926/27/29, LPC2930, and LPC2939 only.

2. ADC functional description

The ADC block contains two conversion channels for each input. Therefore, each ADC
contains a total of 16 channels connected to 8 input pins. Each input is connected to two
channels: input 0 to channels 0 and 8, input 1 to channels 1 and 9, and so forth - see
Figure
conversion. All selected channels are converted sequentially at each conversion scan.
The conversion can have a resolution of between two and 10 bits, configurable per
channel, and it can be either a single or a continuous scan. The conversion scan is started
either immediately by software or waits for an external trigger (a timer event or transition
on an external input).
The main control of the ADC is via the ADC control register (ACON). This register allows
enabling or disabling the ADC, defining the scan mode – single-shot or continuous – and
the channel trigger mode, and it also contains the notification of whether a conversion is
UM10316
User manual
UM10316

Chapter 26: LPC29xx Analog-to-Digital Converter (ADC)

Rev. 3 — 19 October 2010
26–115. Each of these channels can be selected for the analog-to-digital
Analog
Inputs
IN 0
IN 1
IN 2
IN 3
IN 4
IN 5
IN 6
IN 7
I/O pin
GPIO
or
Timer
Fig 115. Schematic representation of the analog to digital converter
Rev. 3 — 19 October 2010
f
i(ADC)
Channel 0
Channel 1
Channel 2
Channel 3
Converter
Channel 4
Channel 5
Channel 6
Channel 7
Channel 8
Channel 9
Channel 10
Channel 11
Channel 12
Channel 13
Channel 14
Channel 15
start
External Trigger Start Immediate
ACON.ASC
scan config
User manual
ACD0
Conversion Data
ACD1
registers
ACD2
ACD3
ACD4
ACD5
ACD6
ACD7
ACD8
Conversion Data
ACD9
registers
ACD10
ACD11
ACD12
ACD13
ACD14
ACD15
'1'
© NXP B.V. 2010. All rights reserved.
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