![NXP Semiconductors LPC84x Скачать руководство пользователя страница 451](http://html.mh-extra.com/html/nxp-semiconductors/lpc84x/lpc84x_user-manual_1721742451.webp)
UM11029
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2017. All rights reserved.
User manual
Rev. 1.0 — 16 June 2017
451 of 515
NXP Semiconductors
UM11029
Chapter 26: LPC84x 12-bit Analog-to-Digital Converter (ADC)
28
SINGLESTEP
When this bit is set, a hardware trigger or a write to the START bit
will launch a single conversion on the next channel in the sequence
instead of the default response of launching an entire sequence of
conversions. Once all of the channels comprising a sequence have
been converted, a subsequent trigger will repeat the sequence
beginning with the first enabled channel.
Interrupt generation will still occur either after each individual
conversion or at the end of the entire sequence, depending on the
state of the MODE bit.
0
29
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
N/A
30
MODE
Indicates whether the primary method for retrieving conversion
results for this sequence will be accomplished via reading the global
data register (SEQB_GDAT) at the end of each conversion, or the
individual channel result registers at the end of the entire sequence.
Impacts when conversion-complete interrupt/DMA trigger for
sequence-B will be generated and which overrun conditions
contribute to an overrun interrupt as described below:
0
0
End of conversion. The sequence B interrupt/DMA flag will be set at
the end of each individual A/D conversion performed under
sequence B. This flag will mirror the DATAVALID bit in the
SEQB_GDAT register.
The OVERRUN bit in the SEQB_GDAT register will contribute to
generation of an overrun interrupt if enabled.
1
End of sequence. The sequence B interrupt/DMA flag will be set
when the entire set of sequence B conversions completes. This flag
will need to be explicitly cleared by software or by the DMA-clear
signal in this mode.
The OVERRUN bit in the SEQB_GDAT register will NOT contribute
to generation of an overrun interrupt since it is assumed this register
will not be utilized in this mode.
31
SEQB_ENA
Sequence Enable. In order to avoid spuriously triggering the
sequence, care should be taken to only set the SEQA_ENA bit when
the selected trigger input is in its INACTIVE state (as defined by the
TRIGPOL bit). If this condition is not met, the sequence will be
triggered immediately upon being enabled.
0
0
Disabled. Sequence B is disabled. Sequence B triggers are ignored.
If this bit is cleared while sequence B is in progress, the sequence
will be halted at the end of the current conversion. After the
sequence is re-enabled, a new trigger will be required to restart the
sequence beginning with the next enabled channel.
1
Enabled. Sequence B is enabled.
Table 445. A/D Conversion Sequence A Control Register (SEQA_CTRL, address 0x4001 C008) bit description
Bit
Symbol
Value
Description
Reset
value