
UM10800
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© NXP Semiconductors N.V. 2016. All rights reserved.
User manual
Rev. 1.2 — 5 October 2016
163 of 487
NXP Semiconductors
UM10800
Chapter 12: LPC82x DMA controller
12.3.2 Trigger outputs
Each channel of the DMA controller provides a trigger output. This allows the possibility of
using the trigger outputs as a trigger source to a different channel in order to support
complex transfers on selected peripherals. This kind of transfer can, for example, use
more than one peripheral DMA request. An example use would be to input data to a
holding buffer from one peripheral, and then output the data to another peripheral, with
both transfers being paced by the appropriate peripheral DMA request. This kind of
operation is called “chained operation” or “channel chaining”.
12.3.3 DMA requests
DMA requests are directly connected to the peripherals. Each channel supports one DMA
request line and one trigger input which is multiplexed to many possible input sources.
For each trigger multiplexer DMA_ITRIG_INMUXn, the following sources are supported:
•
ADC sequence A interrupt ADC_SEQA_IRQ
•
ADC sequence B interrupt ADC_SEQB_IRQ
•
SCT DMA request 0 SCT_DMA0
•
SCT DMA request 1 SCT_DMA1
•
GPIO pin interrupt 0 (PININT0)
•
GPIO pin interrupt 1 (PININT1)
•
Two choices of one of the DMA output triggers
Table 148. DMA requests
DMA channel #
Request input
DMA trigger multiplexer
0
USART0_RX_DMA
DMA_ITRIG_INMUX0
1
USART0_TX_DMA
DMA_ITRIG_INMUX1
2
USART1_RX_DMA
DMA_ITRIG_INMUX2
3
USART1_TX_DMA
DMA_ITRIG_INMUX3
4
USART2_RX_DMA
DMA_ITRIG_INMUX4
5
USART2_TX_DMA
DMA_ITRIG_INMUX5
6
SPI0_RX_DMA
DMA_ITRIG_INMUX6
7
SPI0_TX_DMA
DMA_ITRIG_INMUX7
8
SPI1_RX_DMA
DMA_ITRIG_INMUX8
9
SPI1_TX_DMA
DMA_ITRIG_INMUX9
10
I2C0_SLV_DMA
DMA_ITRIG_INMUX10
11
I2C0_MST_DMA
DMA_ITRIG_INMUX11
12
I2C1_SLV_DMA
DMA_ITRIG_INMUX12
13
I2C1_MST_DMA
DMA_ITRIG_INMUX13
14
I2C2_SLV_DMA
DMA_ITRIG_INMUX14
15
I2C2_MST_DMA
DMA_ITRIG_INMUX15
16
I2C3_SLV_DMA
DMA_ITRIG_INMUX16
17
I2C3_MST_DMA
DMA_ITRIG_INMUX17