Motorola MC68340 User Manual

MOTOROLA

6- 1

The direct memory access (DMA) controller module provides for high-speed transfer
capability to/from an external peripheral or for memory-to-memory data transfer. The DMA
module, shown in Figure 6-1, provides two channels that allow byte, word, or long-word
operand transfers. These transfers can be either single or dual address and to either on-
or off-chip devices. The DMA contains the following features:

• Two, Independent, Fully Programmable DMA Channels

• Single-Address Transfers with 32-Bit Address and 32-Bit Data Capability

• Dual-Address Transfers with 32-Bit Address and 16-Bit Data Capability

• Two 32-Bit Transfer Counters

• Four 32-Bit Address Pointers That Can Increment or Remain Constant

• Operand Packing and Unpacking for Dual-Address Transfers

• Supports All Bus-Termination Modes

• Provides Two-Clock-Cycle Internal Module Access

• Provides Two-Clock-Cycle External Access Using MC68340 Chip Selects

• Provides Full DMA Handshake for Burst Transfers and Cycle Steal

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INTERRUPT

ARBITRATION

SLAVE BIU

MASTER BIU

BUS

ARBITRATION

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M
B

DMA CHANNEL 2

DMA CHANNEL 1

DMA
HANDSHAKE
SIGNALS

DMA
HANDSHAKE
SIGNALS

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Freescale Semiconductor, Inc.

For More Information On This Product,

   Go to: www.freescale.com

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