June 2012
Altera Corporation
Stratix V Hard IP for PCI Express
1. Datasheet
This document describes both the Altera
®
Stratix
®
V Hard IP for PCI Express
®
and
Avalon
®
-MM Stratix V Hard IP for PCI Express MegaCore functions. PCI Express is a
high-performance interconnect protocol for use in a variety of applications including
network adapters, storage area networks, embedded controllers, graphic accelerator
boards, and audio-video products. The PCI Express protocol is software
backwards-compatible with the earlier PCI and PCI-X protocols, but is significantly
different from its predecessors. It is a packet-based, serial, point-to-point interconnect
between two devices. The performance is scalable based on the number of lanes and
the generation that is implemented. Altera offers a configurable hard IP block in
Stratix V devices for both Endpoints and Root Ports that is compliant with
. Using a configurable hard IP block, rather than programmable
logic, saves significant FPGA resources. The hard IP block is available in ×1, ×4, and
×8 configurations.
shows the aggregate bandwidth of a PCI Express link for
Gen1, Gen2, and Gen3 for 1, 4, and 8 lanes. The protocol specifies 2.5 giga-transfers
per second for Gen1, 5 giga-transfers per second for Gen2, and 8.0 giga-transfers per
second for Gen3.
provides bandwidths for a single transmit (TX) or receive
(RX) channel, so that the numbers in
double for duplex operation. Gen1 and
Gen2 use 8B/10B encoding which reduces the numbers in
by approximately
20%. In contrast, Gen3 uses 128b/130b encoding to reduce the bandwidth lost to
encoding.
f
PCI Express High Performance Reference Design
calculating bandwidth for the hard IP implementation of PCI Express in many Altera
FPGAs.
Features
Altera’s Stratix V Hard IP for PCI Express and the Avalon-MM Stratix V Hard IP for
PCI Express IP cores support the following key features:
■
Complete protocol stack including the Transaction, Data Link, and Physical Layers
implemented as hard IP.
■
Feature rich:
■
Support for ×1, ×4, and ×8 configurations with Gen1, Gen2, or Gen3 lane rates
Table 1–1. PCI Express Bandwidth
Link Width
×1
×4
×8
PCI Express Gen1 (2.5 Gbps)
2.5
10
20
PCI Express Gen2 (5.0 Gbps)
5
20
40
PCI Express Gen3 (8.0 Gbps)
8
32
64
June 2012
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