
DR
AFT
DR
AFT
DRAFT
DR
D
RAFT
DRAFT
DRA
FT DRAF
D
RAFT DRAFT DRAFT DRAFT DRAFT D
DRAFT
D
RAFT DRA
FT DRAFT DRAFT DRAFT DRA
UM10360_0
© NXP B.V. 2009. All rights reserved.
User manual
Rev. 00.06 — 5 June 2009
555 of 808
NXP Semiconductors
UM10360
Chapter 29: LPC17xx Analog-to-Digital Converter (ADC)
5.6 A/D Trim register (ADTRIM - 0x4003 4034)
This register will be set by the bootcode on start-up. It contains the trim values for the DAC
and the ADC. The offset trim values for the ADC can be overwritten by the user. All 12 bits
are visible when this register is read.
6.
Operation
Once an ADC conversion is started, it cannot be interrupted. A new software write to
launch a new conversion or a new edge-trigger event will be ignored while the previous
conversion is in progress.
6.1 Hardware-triggered conversion
If the BURST bit in the ADCR is 0 and the START field contains 010-111, the ADC will
start a conversion when a transition occurs on a selected pin or Timer Match signal. The
choices include conversion on a specified edge of any of 4 Match signals, or conversion
on a specified edge of either of 2 Capture/Match pins. The pin state from the selected pad
or the selected Match signal, XORed with ADCR bit 27, is used in the edge detection
logic.
6.2 Interrupts
An interrupt request is asserted to the NVIC when the DONE bit is 1. Software can use the
Interrupt Enable bit for the A/D Converter in the NVIC to control whether this assertion
results in an interrupt. DONE is negated when the ADDR is read.
11
OVERRUN3
This bit mirrors the OVERRRUN status flag from the result register for A/D channel 3.
0
12
OVERRUN4
This bit mirrors the OVERRRUN status flag from the result register for A/D channel 4.
0
13
OVERRUN5
This bit mirrors the OVERRRUN status flag from the result register for A/D channel 5.
0
14
OVERRUN6
This bit mirrors the OVERRRUN status flag from the result register for A/D channel 6.
0
15
OVERRUN7
This bit mirrors the OVERRRUN status flag from the result register for A/D channel 7.
0
16
ADINT
This bit is the A/D interrupt flag. It is one when any of the individual A/D channel Done
flags is asserted and enabled to contribute to the A/D interrupt via the ADINTEN register.
0
31:17
-
Reserved, user software should not write ones to reserved bits. The value read from a
reserved bit is not defined.
NA
Table 517: A/D Status register (AD0STAT - address 0x4003 4030) bit description
Bit
Symbol
Description
Reset
value
Table 518: A/D Trim register (ADTRM - address 0x4003 4034) bit description
Bit
Symbol
Description
Reset
value
3:0
-
reserved.
NA
7:4
ADCOFFS
Offset trim bits for ADC operation. Initialized by the boot code. Can be
overwritten by the user.
0
11:8
TRIM
written-to by boot code. Can
not
be overwritten by the user. These
bits are locked after boot code write.
0
31:1
2
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
NA