Datasheet

Address SpaceAddress Space
DMA
Controller
Address Space Address Space
DMA
Controller
DMA
Controller
DMA
Controller
Fixed Address To Block Of Addresses
Fixed Address To Fixed Address
Block Of Addresses To Fixed Address
Block Of Addresses To Block Of Addresses
DMA Operation www.ti.com
6.2 DMA Operation
The DMA controller is configured with user software. The setup and operation of the DMA is discussed in
the following sections.
6.2.1 DMA Addressing Modes
The DMA controller has four addressing modes. The addressing mode for each DMA channel is
independently configurable. For example, channel 0 may transfer between two fixed addresses, while
channel 1 transfers between two blocks of addresses. The addressing modes are shown in Figure 6-2.
The addressing modes are:
• Fixed address to fixed address
• Fixed address to block of addresses
• Block of addresses to fixed address
• Block of addresses to block of addresses
The addressing modes are configured with the DMASRCINCRx and DMADSTINCRx control bits. The
DMASRCINCRx bits select if the source address is incremented, decremented, or unchanged after each
transfer. The DMADSTINCRx bits select if the destination address is incremented, decremented, or
unchanged after each transfer.
Transfers may be byte-to-byte, word-to-word, byte-to-word, or word-to-byte. When transferring word-to-
byte, only the lower byte of the source-word transfers. When transferring byte-to-word, the upper byte of
the destination-word is cleared when the transfer occurs.
Figure 6-2. DMA Addressing Modes
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DMA Controller SLAU144J–December 2004–Revised July 2013
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