HomeGate Backplane Solutions

Brian Von Herzen, Ph.D.BrianVon@FPGA.com Xilinx ConsultantJune 21, 2004

ISO/IEC JTC1 SC25/WG1 N1118

23 June 2004 (Von Herzen, Chitose)

Problem Statement

• Homegate needs hardware solutions near-term.• Key applications include HDTV input, output and

processing elements.• Compressed HDTV streams may utilize 25 Mbps

bandwidth up to several hundred Mbps bandwidth• Uncompressed HDTV streams require bandwidths of 1.5

Gbps• How can Homegate handle HDTV streams cost-

effectively?

Strategic Objectives

Designing HomeGate hardware for the HDTV 1.5 Gbps bandwidth requirement is a key step to ensuring its relevance over the coming decade for use in the home.

Rapid adoption of Homegate requires having a hardware infrastructure available so that new Homegate card and system vendors can get up to speed quickly and develop new hardware with a minimum of engineering development costs.

Possible Solutions

• Possible backplane electrical standards include– 100Base-T– MII (100 Mbps)– GMII (1 Gbps)– XGMII (10 Gbps)– 1000-Base-CX (1 Gbps)– Aurora (Single-lane XAUI, 3.125 Gbaud)– PCI Express– Serial Rapid IO (2.5 Gbaud)

Lesson from the PC Industry

• Intel has moved from PCI to AGP to PCI-X to PCI-Express. Namely from parallel to serial bus solutions.

• They have determined that multi-gigabit serial solutions offer better price-performance than parallel backplane solutions.

• Homegate can ride the current price-performance improvement wave of bit-serial multi-gigabit transceiver solutions and avoid the cost of parallel backplane buses entirely.

Good News

• A wide variety of FPGA, ASIC, ASSP (application-specific standard products) and processor firms have embraced serial multi-gigabit solutions in their existing product families.

• These products are now riding a steep cost-reduction curve to enable cost-effective bit-serial solutions in today’s marketplace.

Interconnect

• For backplane-based Homegate applications, multi-gigabit serial solutions provide maximum data bandwidth using the minimum number of electrical connections

• For distributed Homegate applications, multi-gigabit cabling such as Serial ATA cables provide cost-effective yet robust interconnect.

• Full-mesh architectures are available, eliminating the need for a central switch card.

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Fabric Topologies: Full-Mesh

• In a Full-Mesh Each Node Has a Direct Connection to Every Other Node

• Switch Fabric is Distributed Across Line Cards

• REDUCED cost of entry for a base-level Homegate system

• No switch-card needed

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Central Switch

Fabric Topologies: Star

• A Star Uses a Centralized Switch Fabric

• Redundant Switch Fabrics are Typically Used for Fault Tolerance

• Switch card is needed even for a 2-slot application.

• Increased cost of entry

Fabric topology for Homegate

• If Homegate implements a full-mesh topology, every card has a direct connection to every other card.

• Entry-level costs of Homegate are lower with a full mesh, since no switch card is needed.

• Using data forwarding, unoccupied cards can increase effective bandwidth to heavily utilized cards.

• Full-mesh implementations are available on FPGA’s today. For example, the MTX core is currently shipping from Xilinx and provides a complete switching solution for full-mesh architectures.

FPGA Solutions

• FPGA’s can help prototype early versions of a new standard like Homegate.

• They provide essential system elements, such as multi-gigabit transceivers (MGT’s), processor cores, logic capability, and dozen’s of IO standards.

• Small FPGA’s enable cost-effective nodes for low-bandwidth applications, while large FPGA’s exceeding 10-million-gates provide high-performance capability for intensive HDTV processing.

Virtex-II Pro™ Platform FPGA

• Virtex®-II Fabric– Upward Compatible– Same Design Tools as other

FPGA’s

• Up to four IBM 405 PowerPCs– Industry standard– 420 DMIPS at 300 MHz

• Up to 24 Serial Transceivers– 622 Mbps to 3.125 Gbps2VP100

Combining Proven Functionalities

Conclusion

• Homegate needs to aim high enough on the performance curve to provide HDTV solutions for the rest of this decade.

• Multi-gigabit performance is required to support uncompressed HDTV applications in the home.

• FPGA’s, ASIC’s and ASSP’s are available today that provide cost-effective multi-gigabit (MGT) serial solutions to the Homegate backplane and cabling requirements.

• FPGA platform technology, including MGT’s, processors, parallel I/O and logic provide a key building block to bootstrapping new standards initiatives and efforts.