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UM10360_0
© NXP B.V. 2009. All rights reserved.
User manual
Rev. 00.06 — 5 June 2009
587 of 808
NXP Semiconductors
UM10360
Chapter 31: LPC17xx General Purpose DMA (GPDMA) controller
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Source and destination burst sizes, 16 transfers.
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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:
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Source start address 0x11200.
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Destination address set to the destination peripheral address.
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Transfer width, word (32-bit).
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Transfer size, 3072 bytes (0xC00).
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Source and destination burst sizes, 16 transfers.
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Next LLI address, 0x0.
Because the next LLI address is set to zero, this is the last descriptor, and the DMA
channel is disabled after transferring the last item of data. The channel is probably set to
generate an interrupt at this point to indicate to the ARM processor that the channel can
be reprogrammed.