Programming the gpdma, 1 enabling the gpdma, 2 disabling the gpdma – NXP Semiconductors LPC24XX UM10237 User Manual

Page 718: Section 32–5

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UM10237_4

© NXP B.V. 2009. All rights reserved.

User manual

Rev. 04 — 26 August 2009

718 of 792

NXP Semiconductors

UM10237

Chapter 32: LPC24XX General Purpose DMA (GPDMA) controller

5.

Programming the GPDMA

The GPDMA enables peripheral-to-memory, memory-to-peripheral,
peripheral-to-peripheral, and memory-to-memory transactions. Each DMA stream is
configured to provide unidirectional DMA transfers for a single source and destination.
The source and destination areas can each be either a memory region or a peripheral
which supports the GPDMA, and must be accessible through AHB1.

The following applies to the registers used in the GPDMA:

Reserved or unused address locations must not be accessed because this can result
in unpredictable behavior of the device.

Reserved or unused bits of registers must be written as zero, and ignored on read
unless otherwise stated in the relevant text.

All register bits are reset to a logic 0 by a system or power-on reset unless otherwise
stated in the relevant text.

Unless otherwise stated in the relevant text, all registers support read and write
accesses. A write updates the contents of a register and a read returns the contents
of the register.

All registers defined in this document can only be accessed using word reads and
word writes (i.e. 32 bit accesses), unless otherwise stated in the relevant text.

5.1 Enabling the GPDMA

To enable the GPDMA set the DMA Enable bit in the DMACConfiguration Register
(

Section 32–6.1.13 “Configuration Register (DMACConfiguration - 0xFFE0 4030)”

.

5.2 Disabling the GPDMA

To disable the GPDMA:

1. Read the DMACEnbldChns Register and ensure that all the DMA channels have

been disabled. If any channels are active, see

Section 32–5.4 “Disabling a DMA

channel”

.

2. Disable the GPDMA by writing 0 to the DMA Enable bit in the DMACConfiguration

Register (

Section 32–6.2.6 “Channel Configuration Registers (DMACC0Configuration

- 0xFFE0 4110 and DMACC1Configuration - 0xFFE0 4130)”

).

SSP1 Rx

3

3

-

-

SD/MMC

4

4

4

4

I

2

S channel 0

-

5

-

-

I

2

S channel 1

-

6

-

-

Table 651. DMA Connections

Peripheral Function DMA Single

Request Input

DMA Burst
Request Input

DMA Last Word
Request Input

DMA Last Burst
Request Input

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