Scatter-Gather DMA Controller

Overview

Direct Memory Access (DMA) is a technique for transferring blocks of data between system memory and peripherals without a processor (e.g., system CPU) having to be involved in each transfer. DMA not only offloads a system’s processing elements, but can transfer data at much higher rates than processor reads and writes.

Scatter-Gather DMA augments this technique by providing data transfers from one non-contiguous block of memory to another by means of a series of smaller contiguous-block transfers. The Lattice Scatter-Gather DMA Controller core implements a configurable, multi-channel, WISHBONE-compliant DMA controller with scatter-gather capability.

Key Features

  • Supports up to 16 physical channels
  • Up to 8 sub-channels per physical channel
  • Four priority levels using round-robin arbitration (weighted or simple)
  • WISHBONE bus widths from 8 to 128 bits
  • Simple DMA, split transfers, scatter-gather
  • Direct interface to external RAM for packet buffering
  • Autonomous and hardware-directed retry
  • Supports WISHBONE burst and classic-cycle transfers
  • Supports centralized and distributed DMA control architectures

Block Diagram

Scatter-Gather DMA Controller Block Diagram

Technical Specifications

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Semiconductor IP