Datasheet

Product data sheet Rev. 4.2 — 18 August 2014 70 of 155

NXP Semiconductors

LPC4350/30/20/10

32-bit ARM Cortex-M4/M0 microcontroller

7.17 AHB peripherals

7.17.1 General-Purpose DMA (GPDMA)

The DMA controller allows peripheral-to memory, memory-to-peripheral,

peripheral-to-peripheral, and memory-to-memory transactions. Each DMA stream

provides unidirectional serial DMA transfers for a single source and destination. For

example, a bidirectional port requires one stream for transmit and one for receives. The

source and destination areas can each be either a memory region or a peripheral for

master 1, but only memory for master 0.

7.17.1.1 Features

• Eight DMA channels. Each channel can support a unidirectional transfer.

• 16 DMA request lines.

• Single DMA and burst DMA request signals. Each peripheral connected to the DMA

Controller can assert either a burst DMA request or a single DMA request. The DMA

burst size is set by programming the DMA Controller.

• Memory-to-memory, memory-to-peripheral, peripheral-to-memory, and

peripheral-to-peripheral transfers are supported.

• Scatter or gather DMA is supported through the use of linked lists. This means that

the source and destination areas do not have to occupy contiguous areas of memory.

• Hardware DMA channel priority.

• AHB slave DMA programming interface. The DMA Controller is programmed by

writing to the DMA control registers over the AHB slave interface.

• Two AHB bus masters for transferring data. These interfaces transfer data when a

DMA request goes active. Master 1 can access memories and peripherals, master 0

can access memories only.

• 32-bit AHB master bus width.

• Incrementing or non-incrementing addressing for source and destination.

• Programmable DMA burst size. The DMA burst size can be programmed to more

efficiently transfer data.

• Internal four-word FIFO per channel.

• Supports 8, 16, and 32-bit wide transactions.

• Big-endian and little-endian support. The DMA Controller defaults to little-endian

mode on reset.

• An interrupt to the processor can be generated on a DMA completion or when a DMA

error has occurred.

• Raw interrupt status. The DMA error and DMA count raw interrupt status can be read

prior to masking.

7.17.2 SPI Flash Interface (SPIFI)

The SPI Flash Interface allows low-cost serial flash memories to be connected to the ARM

Cortex-M4 processor with little performance penalty compared to parallel flash devices

with higher pin count.