Datasheet
UM10398 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2014. All rights reserved.
User manual Rev. 12.3 — 10 June 2014 411 of 547
NXP Semiconductors
UM10398
Chapter 25: LPC111x/LPC11Cxx ADC
[1] Note that this does not require that the timer match function appear on a device pin.
25.5.2 A/D Global Data Register (AD0GDR - 0x4001 C004)
The A/D Global Data Register contains the result of the most recent A/D conversion. This
includes the data, DONE, and Overrun flags, and the number of the A/D channel to which
the data relates.
26:24 START When the BURST bit is 0, these bits control whether and when an A/D conversion is
started:
0
0x0 No start (this value should be used when clearing PDN to 0).
0x1 Start conversion now.
0x2 Start conversion when the edge selected by bit 27 occurs on
PIO0_2/SSEL/CT16B0_CAP0.
0x3 Start conversion when the edge selected by bit 27 occurs on
PIO1_5/DIR/CT32B0_CAP0.
0x4 Start conversion when the edge selected by bit 27 occurs on CT32B0_MAT0
[1]
.
0x5 Start conversion when the edge selected by bit 27 occurs on CT32B0_MAT1
[1]
.
0x6 Start conversion when the edge selected by bit 27 occurs on CT16B0_MAT0
[1]
.
0x7 Start conversion when the edge selected by bit 27 occurs on CT16B0_MAT1
[1]
.
27 EDGE This bit is significant only when the START field contains 010-111. In these cases: 0
0 Start conversion on a rising edge on the selected CAP/MAT signal.
1 Start conversion on a falling edge on the selected CAP/MAT signal.
31:28 - Reserved, user software should not write ones to reserved bits. The value read from a
reserved bit is not defined.
NA
Table 364. A/D Control Register (AD0CR - address 0x4001 C000) bit description
Bit Symbol Value Description Reset
Value
Table 365. A/D Global Data Register (AD0GDR - address 0x4001 C004) bit description
Bit Symbol Description Reset
Value
5:0 - Reserved. These bits always read as zeroes. 0
15:6 V_VREF When DONE is 1, this field contains a binary fraction representing
the voltage on the ADn pin selected by the SEL field, divided by
the voltage on the V
DD
pin. Zero in the field indicates that the
voltage on the ADn pin was less than, equal to, or close to that on
V
SS
, while 0x3FF indicates that the voltage on ADn was close to,
equal to, or greater than that on V
REF
.
X
23:16 - Reserved. These bits always read as zeroes. 0
26:24 CHN These bits contain the channel from which the result bits V_VREF
were converted.
X
29:27 - Reserved. These bits always read as zeroes. 0
30 OVERRUN This bit is 1 in burst mode if the results of one or more conversions
was (were) lost and overwritten before the conversion that
produced the result in the V_VREF bits.
0
31 DONE This bit is set to 1 when an A/D conversion completes. It is cleared
when this register is read and when the ADCR is written. If the
ADCR is written while a conversion is still in progress, this bit is
set and a new conversion is started.
0