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Scatter-Gather Direct Memory Access (DMA) Controller

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IPexpress User Configurable Logo Direct Memory Access (DMA) is a technique for transferrring blocks of data between system memory and peripherals without the intervention of a microprocessor (e.g. system CPU).  Using this technique reduces load on the system processing elements, while enabling much higher data throughput versus using standard processor reand and write transactions.  Scatter-Gather DMA augments this technique by providing data transfers from on non-contiguous block of memory to another by means of a series of small contiguous block transfers.  Lattice's Scatter-Gather DMA Controller IP core provides a master/slave interface, buffer descriptors, and DMA channels.  The core is optimized to work with the Lattice PCI Express soft IP and MACO cores to achieve high-bandwidth PCI Express-based systems with DMA, but can also be used in any system application requiring high data throughput from a host system to a device, or a device to a host system.

 

Features

Top Level IP Support

  • Supports up to 16 Physical Channels
  • Up to 8 Sub-Channels per Physical Channel
  • Supports simple DMA, Split Transfers, and Scatter-Gather DMA
  • Four Priority Levels using Weighted Round-Robin Arbitration
  • Supports Centralized and Distributed DMA Control Architectures
  • Direct Interface to External RAM for Packet Buffering
  • Autonomous and Hardware-Directed Retry
  • WISHBONE Bus Widths from 8 to 128 Bits
  • Supports WISHBONE Burst and Classic-Cycle Transfers

 

Performance and Resource Utilization

Results for LatticeSCM1
IPexpress User-Configurable
Mode		 SLICEs LUTs Registers fMAX (MHz)
16 channels, 8 sub-channels, 32-bit address width,
4K packet buffer size, 256 buffer descriptors		 2733  4234  1984 240
4 channels, 4 sub-channels, 32-bit address width,
4K packet buffer size, 16 buffer descriptors		 2061 3317 1308 246
8 channels, 4 sub-channels, 32-bit address width,
4K packet buffer size, 64 buffer descriptors		 2909 4774 1712 234
4 channels, 2 sub-channels, 32-bit address width,
4K packet buffer size, 16 buffer descriptors		 2052 3368 1239 250

1 Performance and utilization characteristics are generated using an LFSCM3GA-25E-6FF1020C with Lattice's ispLEVER 7.0 software. When using this IP core in a different density, package, speed, or grade within the LatticeSCM family, performance and utilization may vary.

Results for LatticeECPM/S1
IPexpress User-Configurable
Mode		 SLICEs LUTs Registers fMAX (MHz)
4 channels, 4 sub-channels, 32-bit address width,
4K packet buffer size, 16 buffer descriptors		 1959
 3050
 1307 158

1 Performance and utilization characteristics are generated using an LFE2M-35E-6F672C with Lattice's ispLEVER 7.0 software. When using this IP core in a different density, package, speed, or grade within the LatticeECP2M/S family, performance and utilization may vary.

Results for LatticeECP21
IPexpress User-Configurable
Mode		 SLICEs LUTs Registers fMAX (MHz)
8 channels, 4 sub-channels, 32-bit address width,
4K packet buffer size, 64 buffer descriptors		 2662
 4205 1728 159

1 Performance and utilization characteristics are generated using an LFE2-35E-6F672C with Lattice's ispLEVER 7.0 software. When using this IP core in a different density, package, speed, or grade within the LatticeECP2 family, performance and utilization may vary.


Results for LatticeXP21
IPexpress User-Configurable
Mode		 SLICEs LUTs Registers fMAX (MHz)
4 channels, 2 sub-channels, 32-bit address width,
4K packet buffer size, 16 buffer descriptors		 1900
 3063
 1251 127

1 Performance and utilization characteristics are generated using an LFXP2-40E-6F6720C with Lattice's ispLEVER 7.0 software. When using this IP core in a different density, package, speed, or grade within the LatticeXP2 family, performance and utilization may vary.

Ordering Information

Part Numbers:
For LatticeSC: DMA-SG-SC-U1
For LatticeECP2: DMA-SG-P2-U1
For LatticeECP2M: DMA-SG-PM-U1
For LatticeXP2: DMA-SG-X2-U1

 

To find out how to evaluate or purchase the Scatter-Gather DMA IP core, please contact your local Lattice Sales Office.