UM10462
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2016. All rights reserved.
User manual
Rev. 5.5 — 21 December 2016
386 of 523
NXP Semiconductors
UM10462
Chapter 19: LPC11U3x/2x/1x ADC
[1]
Note that this does not require that the timer match function appear on a device pin.
19.5.2 A/D Global Data Register (GDR - 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 a trigger signal on
CT16B0_CAP0 (independently of the pinout).
0x3
Start conversion when the edge selected by bit 27 occurs on a trigger input on
CT32B0_CAP0 (independently of the pinout).
0x4
Start conversion when the edge selected by bit 27 occurs on CT32B0_MAT0
0x5
Start conversion when the edge selected by bit 27 occurs on CT32B0_MAT1
0x6
Start conversion when the edge selected by bit 27 occurs on CT16B0_MAT0
0x7
Start conversion when the edge selected by bit 27 occurs on CT16B0_MAT1
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 352. A/D Control Register (CR - address 0x4001 C000) bit description
Bit
Symbol
Value Description
Reset
Value
Table 353. A/D Global Data Register (GDR - address 0x4001 C004) bit description
Bit
Symbol
Description
Reset
Value
5:0
-
Reserved. These bits always read as zeros.
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 zeros.
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 zeros.
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