Xilinx ships the world’s first heterogeneous 3D FPGA

The folks from Xilinx have just announced initial shipments of their Virtex-7 H580T FPGA, which they describe as "The world’s first 3D heterogeneous all programmable product."

Now, it's easy to become confused by just what "heterogeneous" means in this context, so let's take a few moments to set the scene. Consider the image below:


Generally speaking, we are used to monolithic FPGAs as illustrated on the left of this image. In this context, "monolithic" means that there is one silicon die in the package.

In 2011, Xilinx announced the first shipments of its Virtex-7 2000T FPGA (Click Here for more details). The Virtex-7 2000T is currently the world’s highest-capacity programmable logic device – it contains 6.8 billion transistors, providing designers with access to 2 million logic cells. This is equivalent to 20 million ASIC gates, which makes these devices ideal for system integration, ASIC replacement, and ASIC prototyping and emulation.

The capacity is made possible by Xilinx’s Stacked Silicon Interconnect technology. This involves a special layer of silicon known as a "silicon interposer" combined with through-silicon vias (TSVs). In the case of the Virtex-7 2000T, four FPGA dice are attached to the silicon interposer, which – in addition to connecting the FPGAs to each other (~10,000 connections between adjacent dice) – provides connections to the chip package


The thing is that the Virtex-7 2000T is homogeneous, because all four FPGA dice are identical. By comparison, the Virtex-7 H580T is heterogeneous, because it comprises 2X FPGA dice and 1X 8-channel 28Gbps transceiver die in the same package (the forthcoming Virtex-7 H870T will boast 3X FPGA dice and 2X 8-channel 28Gbps transceiver dice in the same package).


The end result is that, using Xilinx’s stacked silicon interconnect (SSI) technology, heterogeneous Virtex-7 HT devices deliver the industry’s highest bandwidth FPGAs, featuring up to sixteen 28 Gbps and seventy-two 13.1 Gbps transceivers, making them the only single-package solutions for addressing key Nx100G and 400G line card applications and functions. Combined with Xilinx’s leading 100G gearbox, Ethernet MAC, OTN and Interlaken IP, Virtex-7 HT devices provide customers with the levels of system integration they need to meet space, power and cost challenges as they transition to CFP2 optical modules.

Consider the image below. One of today's Nx100G solutions requiring five chips can now be implemented using a single Virtex-7 H580T. The result is identical performance with a smaller BOM cost, a significantly lower power consumption, and improved productivity / reduced time to market.


Using SSI technology enables Xilinx to deliver not only high-capacity devices built on TSMC’s 28nm high performance/low power process, but also an unprecedented number of transceivers for unmatched system performance. For example, competing monolithic FPGAs are able to integrate only a fourth of the number of 28 Gbps channels.

The heterogeneous implementation of Virtex-7 HT devices also enables Xilinx to make independent technology choices for the core FPGA and 28 Gbps transceiver die, which avoids burdening the FPGA with high leakage transistors that waste system power and bring no benefit to computation tasks. Having 28 Gbps transceivers on silicon separate from the core FPGA fabric further allows for superior noise isolation, enabling best overall signal integrity and system margin, as well as improved productivity for design closure and faster time to market.

“We were impressed by the low transmit jitter of the Virtex-7 H580T device’s 28 Gbps transceivers and also by how quickly we were able to bring up a functioning link when combined with Luxtera’s 4x28 Gbps single chip silicon photonic transceiver,” said Chris Bergey, Vice President of Marketing at silicon photonics leader Luxtera Inc. “Xilinx has clearly hit an industry milestone with this device because it allows makers of networking systems to easily overcome the challenges they face to enable more bandwidth.”

Effectively upgrading networks to handle exponential growth in data usage is critical to the communications industry. This requires power and port density improvements in optical modules while reducing cost per bit. Driven by the migration to CFP2 and, in the future, CFP4 optical modules, Virtex-7 HT devices enable unprecedented integration capability for communication equipment vendors designing Nx100G and 400G line cards.

“With eight 28 Gbps transceivers and ample logic capacity, the Virtex-7 H580T device is the only FPGA that can integrate additional line card functionality so that designers can implement a dual 100G OTN transponder on a single chip,” said Mark Gustlin, System Architect for Wired Communications at Xilinx. “Competing ASSP-based solutions will comprise five devices, will remain unavailable for more than a year, will consume at least 40 percent additional power and will cost 50 percent more.”

Virtex-7 HT devices with their 28 Gbps transceivers allow support for up to four IEEE 100GE gearboxes in a single device with the option of integrating advanced debug capabilities, OTN, MAC or Interlaken IP within the same FPGA, eliminating the need for separate gearbox and ASSP devices. The upcoming Virtex-7 H870T device is also 400GE ready and will be able to support future 400GE modules that require16x25 Gbps interfaces. The result is reduced overall power and BOM cost and a more flexible solution in the midst of changing protocols.

In Xilinx’s newest 28 Gbps technology video, a Virtex-7 H580T device demonstrates its abilities to deliver the eye and jitter characteristics needed to reach the performance required to interface to CFP2 optic modules. New white papers, videos and more can be found on Xilinx’s 28 Gbps Serial Transceiver Technology page.  


Availability
First silicon Virtex-7 H580T FPGAs are shipping to key customers today with development tool support available in the recently announced Vivado Design Suite. Customers interested in using the Virtex-7 H580T device can contact their local Xilinx representative for further pricing and availability details.

---

If you found this article to be of interest, visit Programmable Logic Designline where – in addition to my Max's Cool Beans blogs – you will find the latest and greatest design, technology, product, and news articles with regard to programmable logic devices of every flavor and size (FPGAs, CPLDs, CSSPs, PSoCs...).

Also, you can obtain a highlights update delivered directly to your inbox by signing up for my weekly newsletter – just Click Here to request this newsletter using the Manage Newsletters tab (if you aren't already a member you'll be asked to register, but it's free and painless so don't let that stop you [grin]).

Last but certainly not least, make sure you check out the daily discussions and other information resources at All Programmable Planet, where we cover everything of interest in "Programmable Space" for everyone from beginners to experts, hardware designers and software developers, and system designers.