Convergence of FPGA and ASIC at nodes of 20nm and 16/14nm

Date: 09/07/2013
Xilinx has announced taping out of 20nm FPGA chip using TSMC fab. The 20nm FPGA which is named as 'Ultrascale family' by Xilinx is expected to be sampled in late 2013 and mass production in 2014. Xilinx is also in full speed to bring 16nm on the design benches of EEs in 2014. Altera is also going fast in bringing 14nm FPGA made by Intel fab sometime during same time. Two more FPGA vendors who are also in the race whose products worth trying are Achronix and Tabola with 22nm Intel made FPGAs. How do these expensive deep node FPGA chips will help chip/system designers in building better products. Here is a brief write-up on the use of 20nm and 16/14nm FPGA ICs.

The ways FPGAs have pushed out ASIC market is history, now they are entering lot more markets/applications by offering programmable silicon advantage. The ASSP/CSSP, SoC and the microcontroller markets are targeted now immediately.

When a mobile phone SoC of 28nm is made using 14nm node. The integration helps the SoC chip to fit into a smart wearable device on your wrist replacing your wrist watch. Mobile phone with 14nm SoC with 4x capabilities of 28nm SoC can do more video processing/analytics of the picture taken from the mobile phone camera, and improved voice to text processing. You can also nearly turn your smart-phone/tablet into a PC/TV/phone by wirelessly connecting to display and storage device of any size seamlessly. These are simple common sense advantages of 14nm node made SoC chips. When you prototype your 14nm SoC design on FPGA you prefer an FPGA made using even deeper nodes. That's the reason why FPGA is mostly the first chip to get sampled from foundries and fabs at deeper nodes. One of the most used application of FPGA is IC-prototyping. The IC prototypers mix and match ASIC blocks with FPGA blocks. With this trend in mind, FPGA vendors offering deep node FPGA chips with important and essential ASIC hard blocks. Also one more trend is 2.5D FPGA modules, which are nothing but multiple FPGAs connected in one next to other on a silicon interposer with multiple interconnects. The advantage of 2.5D is the interchip data speed is far better than PCB assembled FPGA unit. Xilinx started offering 2.5D by using the chips made using 28nm nodes. When the 16nm/14nm are available, 2.5D FPGA module user can replace them with single 16nm/14nm device or make an even more complex 2.5D chips using 16nm/14nm chips. Why this writer is talking about Mobile SoC chips here is, FPGA can become part of SoC to support changing specs of data interfaces.

To give a latest example in prototype application, Aldec has developed its FPGA based HES-7 SoC/ASIC Prototyping Platform for developing SoC and ASIC designs up to 96 million ASIC gates. Aldec has used Xilinx's 28nm node based Virtex-7 and Zynq SoC in assembling HES-7. HES-7 is suitable for SoC designs based on ARM Cortex architecture with high-speed interfaces such as Ethernet, Wi-Fi, Bluetooth, HDMI, and PCI Express.

“HES-7 provides a lot of capability in a little package,” said Northwest Logic’s president, Brian Daellenbach, “The dual Virtex-7 2000T and ARM support, in combination with the Northwest Logic PCIe Cores, enable large SoC, PCIe-based designs to be quickly prototyped with a minimum of design partitioning”.

Well prototyping is traditional area, where FPGAs are used extensively. With power consumption dropping to low levels in deep-node FPGAs, a fabric of FPGA can get into mobile SoC itself to help mobile phone developers to custom design phones and add extra layer of security. Also with the on-chip FPGA, mobile phone designers can reprogram the chip for any emerging video processing and new standards of interface without physically redesigning either chip/board.

The other more important area where FPGAs are centric are telecom networks; both wired and wireless. With the mobile devices featuring high-definition video and the LTE capable of supporting HD video streaming, the network processing engines are fed with 100s and 1000s of streams of digital video. The network device has to process them in real time and send the packets to another sys or network in real-time. So both the quantity and the complexity of data is rising along with the introduction of new standards in video coding and decoding. The new standards are developed to reduce the bandwidth and improve the video quality. So the common factor is 'change of many things with time'.
That's where FPGA fitin, they are both hardware and software configurable. Designer can redesign the FPGA for a new video codec and changing data-speeds. The newer telecom networks work better when they use smaller FPGA with higher gate density. The data-speed bottleneck of interchip and intra-chip communications is going to solved by silicon photonics. Altera is leading in this.

Well these are the traditional FPGA markets. There are new market emerging for FPGA. Xilinx has a successful launched a product called Zynq. It’s a SoC for embedded system applications. It has FPGA fabric plus a complete ASIC system powered by ARM Cortex A7 processor. Many are using this IC in the market for innovative applications. Here in India also, it is quite popular. Altera also has a similar offering. This is the area where many ASIC vendors can make SoC class MCU chips with some amount of FPGA integrated but at deeper nodes. Why because power consumption in FPGA becomes an issue at larger nodes. Cypress Semiconductor is one of the early vendor who is offering such product which is called PSoC. Recently NXP and Microchip have also announced microcontroller chips with some on-chip programmable glue-logic.

Meanwhile let's not forget the FPGA vendor QuickLogic who is offering what is called Customer Specific Standard Products (CSSP), which is a mix of hard logic and FPGA fabric. QuickLogic has its own patented ViaLink technology for reducing the power consumption in FPGA. If an OEM found a market opportunity for a product and wanto deliver that product during holiday season of Christmas and year-end. So it has to design the box and the chip with in 5/6 months or even less, than a FPGA integrated SoC in small packages and consuming less power comes very handy. Lattice Semiconductor and QuickLogic are serving the consumer electronics market with ready reference designs. FPGA to play significant role in consumer market by offering the feature of mass-customization.

So at 16nm/14nm the convergence of FPGAs and ASICs can not be ruled out. At these very realistic nodes, the silicon will not only a software programmable but is also hardware programmable. This will result into enormous scope for custom design, like said "Giga applications from nanoscale".

The future designs going to be mix and match of programmable logic with ASIC blocks, and so is the embedded software which is going to be mix of VHDL and C. FPGA as a block is going to be a fast-growth area, where pure FPGAs may still limited to some applications.

What threatens programmable silicon market! As of now, it looks nothing, but there are couple of things, we will let you know in our next article.

FPGA