Scatter-gather dma controller core, Core overview, Example systems – Altera Embedded Peripherals IP User Manual
Page 192: Scatter-gather dma controller core -1, Core overview -1, Example systems -1
Scatter-Gather DMA Controller Core
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2014.24.07
UG-01085
Core Overview
The Scatter-Gather Direct Memory Access (SG-DMA) controller core implements high-speed data
transfer between two components. You can use the SG-DMA controller core to transfer data from:
• Memory to memory
• Data stream to memory
• Memory to data stream
The SG-DMA controller core transfers and merges non-contiguous memory to a continuous address
space, and vice versa. The core reads a series of descriptors that specify the data to be transferred.
For applications requiring more than one DMA channel, multiple instantiations of the core can
provide the required throughput. Each SG-DMA controller has its own series of descriptors specifying
the data transfers. A single software module controls all of the DMA channels.
For the Nios
®
II processor, device drivers are provided in the Hardware Abstraction Layer (HAL)
system library, allowing software to access the core using the provided driver.
Example Systems
The block diagram below shows a SG-DMA controller core for the DMA subsystem of a printed circuit
board. The SG-DMA core in the FPGA reads streaming data from an internal streaming component and
writes data to an external memory. A Nios II processor provides overall system control.
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