The Trend There is a trend observed in the market for designing products with SuperSpeed USB and NAND Flash inside. There are camera manufacturers, printer manufacturers as well as FLASH drive manufacturers involved in the trend. It is crucial, at this point of time in the market, to have a proper knowhow on what factors affect such designs and what can be done to achieve a successful and a longlife design. SuperSpeed USB The USB 3.0 standard claims that it is 10 times faster than USB 2.0. The theoretical speed is 4.8Gbps (600MBps). However looking at various realistic speed test reports made available by more than one developers, it has been concluded that 400MBps is the maximum achievable speed for this standard. Factors affecting performance Depending on the NAND Flash used in the system, the performance can be estimated. But, there are a number of factors affecting the speed and performance of USB in a system. Eric Huang has listed the dependencies very interestingly in his blog. I am listing them here. The USB transfer speed is affected by the following factors: Number of applications running on the host machine The speed of the application itself The quality of the drivers (host as well as device) The bus on the hardware that moves data from USB controller to CPU (on host as well as device side) The USB PHY The USB Cable Non-ideal system Looking into a nonidealized system, the SLS SuperSpeed USB Device IP Core tests performed on GigaByte A75 Motherboard have indicated the performance ~2.1Gigabits per second (262.5 Megabytes per second) with mass storage interface and ~2.7Gigabits per second (337.5 Megabytes per second) with raw interface. There is a word in the development community about NAND Flash being the bottleneck for USB performance. Lets see how the performance numbers with the NAND Flash look like. Mass storage performance tests with SLS SuperSpeed IP and ONFI controller IP (without ECC overload) have indicated speed upto 101.5 MBps (812 Mbps). What does this mean? Transferring 1 Gb (125MB) data from the flash drive to the PC would take a second, which takes more than 6 seconds at present with USB 2.0 interface and RAM memory Copying 5Gb (625MB) data from flash drive to PC would take 5 seconds, which is right now taking 31 seconds using USB 2.0 interface and RAM memory Data that takes 5 minutes to transfer using USB 2.0 interface and RAM at present (6000MB) would be transferred in 48 seconds! Not bad to have this solution for the current product upgrade...
SUPERSPEED USB and NAND FLASH DESIGNS Date: June 19. 2012 Version: 1.0 Whitepaper There is a trend observed in the market for designing products with SuperSpeed USB and NAND Flash inside. There are camera manufacturers, printer manufacturers as well as FLASH drive manufacturers involved in the trend. It is crucial, at this point of time in the market, to have a proper knowhow on what factors affect such designs and what can be done to achieve a successful and a longlife design. The paper focuses on providing information base required for proceeding with the design and what factors would affect such designs. USB is one of the most successful peripheral that has penetrated heavily into CE and mobile systems. The USB standard is developed by The USB Implementers Forum. The increasing need for higher speeds led to the development of more standards which has led to SuperSpeed USB. The USBIF has put up a video on Vimeo for SuperSpeed USB. It can be viewed at: http://vimeo.com/20616954 SuperSpeed USB features as listed on usb.org are given below: SuperSpeed USB is a SyncNGo technology that minimizes user waittime. SuperSpeed USB will provide Optimized Power Efficiency.No device polling and lower active and idle power requirements. SuperSpeed USB is backwards compatible with USB 2.0. Devices interoperate with USB 2.0 platforms. Hosts support USB 2.0 legacy devices. The USB 3.0 standard claims that it is 10 times faster than USB 2.0. The theoretical speed is 4.8Gbps (600MBps). However looking at various realistic speed test reports made available by more than one developers, it has been concluded that 400MBps is the maximum achievable speed for this standard. The core efficiency is dependent on a number of factors like 8b/10b encoding, packet structure and framing, link level flow control and protocol overhead. At 5Gbps signalling rate with 8b/10b encoding, the raw throughput is 500MBps. When link flow control, packet framing, and protocol overhead are considered, it is realistic for 400MBps or more to be delivered to an application. In an idealized system, as leading experts say, the controllers and PHYs can achieve SuperSpeed USB 3.0 speeds of 400 Megabytes per second (or 4 Gigabits per second). Page 1 of 8 System Level Solutions
Transcript
SUPERSPEED USB and NANDFLASH DESIGNS
Date: June 19. 2012 Version: 1.0
Whitepaper
There is a trend observed in the market for designing products with SuperSpeed USB and NAND Flash inside.There are camera manufacturers, printer manufacturers as well as FLASH drive manufacturers involved in thetrend. It is crucial, at this point of time in the market, to have a proper knowhow on what factors affect suchdesigns and what can be done to achieve a successful and a longlife design. The paper focuses on providinginformation base required for proceeding with the design and what factors would affect such designs.
USB is one of the most successful peripheral that has penetrated heavily into CE and mobilesystems. The USB standard is developed by The USB Implementers Forum. The increasing needfor higher speeds led to the development of more standards which has led to SuperSpeed USB. TheUSBIF has put up a video on Vimeo for SuperSpeed USB. It can be viewed at:http://vimeo.com/20616954SuperSpeed USB features as listed on usb.org are given below:
SuperSpeed USB is a SyncNGo technology that minimizes user waittime.SuperSpeed USB will provide Optimized Power Efficiency.No device polling and lower activeand idle power requirements.SuperSpeed USB is backwards compatible with USB 2.0. Devices interoperate with USB 2.0platforms. Hosts support USB 2.0 legacy devices.
The USB 3.0 standard claims that it is 10 times faster than USB 2.0. The theoretical speed is4.8Gbps (600MBps). However looking at various realistic speed test reports made available by morethan one developers, it has been concluded that 400MBps is the maximum achievable speed for thisstandard.The core efficiency is dependent on a number of factors like 8b/10b encoding, packet structure andframing, link level flow control and protocol overhead.At 5Gbps signalling rate with 8b/10b encoding, the raw throughput is 500MBps. When link flowcontrol, packet framing, and protocol overhead are considered, it is realistic for 400MBps or more tobe delivered to an application.In an idealized system, as leading experts say, the controllers and PHYs can achieve SuperSpeedUSB 3.0 speeds of 400 Megabytes per second (or 4 Gigabits per second).
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WHAT IS NAND FLASH?NAND Flash is a nonvolatile memory chip used for storage generally in flash drives, SD Cards, SSDsetc. The standard is developed by ONFI (Open NAND Flash Interface), which is a workgroupconsisting of multiple companies and involved in designing, enabling and simplifying the integration ofthe NAND Flash into various electronic products.NAND Flash devices can be found in different variants and can be selected depending on the cost,size and usage model. Some NAND Flash memories are slower and cheaper, while some are fasterand quite expensive. Therefore, a NAND Flash used in a Flash drive will be different than the oneused in an ultrabook!
WHAT AFFECTS THE PERFORMANCE?Depending on the NAND Flash used in the system, the performance can be estimated. But, there area number of factors affecting the speed and performance of USB in a system. Eric Huang has listedthe dependencies very interestingly in his blog. I am listing them here.The USB transfer speed is affected by the following factors:
Number of applications running on the host machineThe speed of the application itselfThe quality of the drivers (host as well as device)The bus on the hardware that moves data from USB controller to CPU (on host as well as deviceside)The USB PHYThe USB Cable
A NON-IDEALIZED SYSTEMLooking into a nonidealized system, the SLS SuperSpeed USB Device IP Core tests performed onGigaByte A75 Motherboard have indicated the performance ~2.1Gigabits per second (262.5Megabytes per second) with mass storage interface and ~2.7Gigabits per second (337.5Megabytes per second) with raw interface.About SLS SuperSpeed USB Device IP CoreThe SLS SuperSpeed USB device core supports connectivity between TI USB3.0 Phy (TUSB1310 ) and Altera FPGA.
The Core is wrapped around withsoftware drivers and examples for itsease of use and quick integration.
The core package also contains thereference design that can be useddirectly for starting a customapplication development.
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The SystemGiven below is the diagram of the design used for the performance testing of the nonideal system.
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The speed numbers mentioned previously are the result of tests performed on SLS USB 3.0DevelopmentAbout SLS USB 3.0 Development Board
USB 3.0 development board provides a hardware and software platform fordeveloping and prototyping SuperSpeed USB 3.0 device interfaceapplications.
The board featured with Altera's lowest cost, lowest power and highfunctionality Cyclone IV E FPGA family device. It uses TUSB1310AZAYUSB 3.0 PHY Chip for USB 3.0 SuperSpeed device interface.
Also the board enriched with the highspeed memory components likeDDR2 SDRAM, NAND Flash, CFI Flash, SDRAM and SD card as externalmemory storage media.
There is a word in the development community about NAND Flash being the bottleneck for USBperformance.Lets see how the performance numbers with the NAND Flash look like. Mass storage performancetests with SLS SuperSpeed IP and ONFI controller IP (without ECC overload) have indicated speedupto 101.5 MBps (812 Mbps).What does this mean?
Transferring 1 Gb (125MB) data from the flash drive to the PC would take a second, whichtakes more than 6 seconds at present with USB 2.0 interface and RAM memoryCopying 5Gb (625MB) data from flash drive to PC would take 5 seconds, which is right now
taking 31 seconds using USB 2.0 interface and RAM memoryData that takes 5 minutes to transfer using USB 2.0 interface and RAM at present (6000MB)would be transferred in 48 seconds!
Not bad to have this solution for the current product upgrade...Let us have a look at the development systems available to get this done.
DEVELOPMENT SYSTEMSSLS has a number of options available for developers intending to integrate NAND Flash and USBtechnology in their designs.NAND Flash IP CoresNAND Flash Controller IP Cores from SLS are the intermediate stage between NAND Flash memoryand master controller. It is designed to have high speed solution to manage NAND Flash application.They support Open NAND Flash Interface Working Group (ONFI) standard.Two advanced architectures register based and descriptor based, provides high speed performance,software flexibility, data integrity and device compatibility. Descriptor based architecture reducesamount of CPU intervention.There are two variants available1. ONFI Controller
2. ECNAND Controller
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USB IP CoresThe SLS USB IP Cores support SuperSpeed (5Gbps), High Speed (480 Mbps) and Full Speed (12Mbps) functionality alongwith three preconfigured endpoints Control, IN, and OUT. It can beconfigurable up to 15 IN/OUT endpoints on customer request on chargeable basis. Each configurableendpoint has an endpoint controller that supports interrupt, bulk, and isochronous transfers.The core has been optimized for Altera FPGAs and its functionality has been verified on the hardwarewith Altera Quartus II. The package includes ModelSim precompiled library for core simulation andverification.Given below are the core variants available.1. USB20SR USB 2.0 Device IP Core withSoftware based Enumeration
2. USB20HF USB 2.0 Device IP Core with FIFOInterface
3. USB20HC USB 2.0 Host Controller IP Core
4. USB30SF USB 3.0 Device IP Core (SuperSpeed Core)
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Hardware PlatformsThere are three options for hardware platform to choose for USB and NAND Flash design prototypesystems.1. ONFI 2.0 HSMC Snap On BoardThe ONFI 2.0 HSMC ( High SpeedMezzanine Card) is designed to developNAND Flash based applications withDevelopment boards having the HighSpeed Mezzanine Card (HSMC)connector.The board provides connectivity to eight16Gb NAND Flash devices and one HighSpeed Transceiver Transmit and Receivechannel via SMA connectors.
2. CoreCommander Development Board (Cyclone IIIFPGA with USB 2.0 Interface)CoreCommander development board is unique in theindustry. It features the Altera Cyclone III FPGA thatprovides more than enough room for almost anyembedded design.This flexible board comes with a suite of SLS IP Cores,drivers, and application software.Delivered as a complete package, the board and softcontent ensures quick and easy implementation of
industry leading cores with reduced risk AND at a very low cost.3. USB 3.0 Development Board (Cyclone IV FPGA)USB 3.0 development board provides a hardwareand software platform for developing andprototyping SuperSpeed USB 3.0 device interfaceapplications.The board featured with Altera's lowest cost,lowest power and high functionality Cyclone IV EFPGA family device. It uses TUSB1310AZAYUSB 3.0 PHY Chip for USB 3.0 SuperSpeeddevice interface.Also the board enriched with the highspeedmemory components like DDR2 SDRAM, NAND Flash, CFI Flash, SDRAM and SD card as externalmemory storage media.
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ASSP or ASIC or FPGA?One superimportant question that would pop up at this point or earlier is whether ASSP or ASIC orFPGA should be chosen as a preferred solution for design. ASSPs have a limited number of functionsimplemented and in order to add a functionality that is not available in the current ASSP, we either needto change the ASSP or add a new chip in the design. Addition of custom logic is very very difficult forASSP and that is why FPGAs and ASICs are preferredLet us take a look at a few design aspects to choose between FPGA and ASIC.Cost and Time to MarketMost of the projects are called off due to time to market and cost reasons. Some large ASICs take ayear or more to design. One of the ways to shorten the development time is to make prototype usingFPGAs and then switch to an ASIC. Structured ASIC is one of the solution.The NRE charges are high when choosing an ASIC development route. Looking at FPGA developmentroute, there are a number of tools available online with a license fee which is quite small as comparedto the NRE paid for ASIC development. Since FPGAs are fully fabricated, there are no NRE charges tobe paid to the FPGA vendor. Structured ASICs and FPGAs are much more attractive solution whentaking this factor into considerationModern FPGA featuresFPGAs, today, are available at low cost and have features like PLLs, Low voltage differential signalling,clock data recovery, internal routing and control (with advanced EDA tools available), high speed,hardware multipliers for DSPs, programmable I/Os and much more. Additionally, there are a number ofIP cores available today as option to start development. The FPGA design flow has become very muchclose to ASIC due to the flexibility provided by the vendors in the EDA tools.Looking at all these features, it becomes tough for ASIC to compete here.Design Changes/EnhancementsFPGAs can be reprogrammed in few hours while an ASIC can take $50,000 and six weeks to make thechanges. FPGA costs start from a couple of dollars to several hundred or more depending on thefeatures listed above.
In this age with increasing demand for new products/features and rapid changes in the industry, FPGAsseem to be the safe and convenient developmentroute. However, the chart on the left posted fromeetimes.com will shed some more light on making achoice between ASIC and FPGA.Appropriate choice can be made after considering allthe aspects of the design.
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ABOUT SLSSystem Level Solutions is an integration specialist providing the most innovative creative solutionsspanning intellectual property, hardware/software design, and manufacturing. SLS provides a widerange of specialized design tools, IP cores, and products to help you achieve a winning product, and getit to market rapidly. Let SLS enhance and expedite your design.SLS provides unprecedented creativity and integration know how that helps designers maneuver thepitfalls inherent in combining disparate hardware, software and IP. SLS not only provides IP as a corecompetency, design services and manufacturing complete the effort so that you have the help youneed, from inception to completionor anywhere in between.SLS offers a widerange of capabilities including: USB 3.0, USB 2.0, SD Host and many more cores,development boards, software and services all at a reasonable price.SLS integrated solutions work the first time.
