V-Series Avalon-MM DMA Interface for PCIe Solutions User Guide

ID 683514
Date 7/31/2018
Public
Document Table of Contents

1.1. V-Series Avalon-MM DMA Interface for PCIe* Datasheet

Intel ® V-Series FPGAs include a configurable, hardened protocol stack for PCI Express* that is compliant with PCI Express Base Specification 2.1 or 3.0.

The V-Series Avalon® Memory-Mapped (Avalon-MM) DMA for PCI Express removes some of the complexities associated with the PCIe* protocol. For example, the IP core handles TLP encoding and decoding. In addition, it includes Read DMA and Write DMA engines. If you have already architected your own DMA system with the Avalon-MM interface, you may want to continue to use it. However, you may want to take advantage of the simplicity of having the DMA engines already implemented. Intel recommends this variant for new users. Depending of the device you select, this variant is available in Platform Designer for 128- and 256-bit interfaces to the Application Layer. The Avalon-MM interface and DMA engines are implemented in FPGA soft logic.

Figure 1.  V-Series PCIe Variant with Avalon-MM DMA InterfaceThe following figure shows the high-level modules and connecting interfaces for this variant.
Note: This variant was renamed in the Quartus® II 14.0 release. The name in the Quartus II 13.1 release was Avalon-MM 256-bit Hard IP for PCI Express IP Core.
Table 1.  PCI Express Data Throughput

The following table shows the aggregate bandwidth of a PCI Express link for Gen1, Gen2, and Gen3 for 2, 4, and 8 lanes. The protocol specifies 2.5 giga-transfers per second for Gen1, 5.0 giga-transfers per second for Gen2, and 8.0 giga‑transfers per second for Gen3. This table provides bandwidths for a single transmit (TX) or receive (RX) channel. The numbers double for duplex operation. Gen1 and Gen2 use 8B/10B encoding which introduces a 20% overhead. In contrast, Gen3 uses 128b/130b encoding which introduces only a 1.5% overhead.

Units are Gigabits per second (Gbps).

Link Width
×2 ×4 ×8

PCI Express Gen1 (2.5 Gbps)

N/A N/A

16 Gbps

PCI Express Gen2 (5.0 Gbps)

8 Gbps

16 Gbps

32 Gbps

PCI Express Gen3 (8.0 Gbps)

15.75 Gbps

31.51 Gbps

63Gbps