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UM10316_0
© NXP B.V. 2008. All rights reserved.
User manual
Rev. 00.06 — 17 December 2008
537 of 571
NXP Semiconductors
UM10316
Chapter 30: LPC29xx General Purpose DMA (GPDMA) controller
The first LLI, stored at 0x20000, defines the first block of data to be transferred, which is
the data stored between addresses 0x0A200 and 0x0AE00:
•
Source start address 0x0A200.
•
Destination address set to the destination peripheral address.
•
Transfer width, word (32-bit).
•
Transfer size, 3072 bytes (0XC00).
•
Source and destination burst sizes, 16 transfers.
•
Next LLI address, 0x20010.
The second LLI, stored at 0x20010, describes the next block of data to be transferred:
•
Source start address 0x0B200.
•
Destination address set to the destination peripheral address.
•
Transfer width, word (32-bit).
•
Transfer size, 3072 bytes (0xC00).
•
Source and destination burst sizes, 16 transfers.
•
Next LLI address, 0x20020.
A chain of descriptors is built up, each one pointing to the next in the series. To initialize
the DMA stream, the first LLI, 0x20000, is programmed into the DMA Controller. When the
first packet of data has been transferred the next LLI is automatically loaded.
The final LLI is stored at 0x20070 and contains:
•
Source start address 0x11200.
•
Destination address set to the destination peripheral address.
•
Transfer width, word (32-bit).
•
Transfer size, 3072 bytes (0xC00).
•
Source and destination burst sizes, 16 transfers.
•
Next LLI address, 0x0.
Fig 134. LLI example