EEWeb Pulse - Volume 108 by EEWeb Magazines

S i mo nS e g a r s

C E Oo f ARM

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CONTENTS

PULSE

Simon Segars

CEO of ARM

How this relatively small semiconductor IP company became one of the world’s leading processor providers.

Featured Products

This week’s latest products from EEWeb.

The New ARM Cortex-A12 CPU

ARM targets the midpoint cellphone market with the brand new A12 processor.

Microchip’s Broad Wireless Portfolio Expansion

These next-generation RF products are integral in making Microchip a leader in embedded wireless solutions.

Selecting the Right Hard Disk Drive

An overview of the key characteristics to look for when selecting one of the most important parts of a computer.

26 14

RTZ

Return to Zero Comic

10 14 20 26 30

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PULSE

Simo

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INTERVIEW

on Segars - CEO

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PULSE

What do you think are the key factors that have led to ARM’s success? The company is still quite small and I think that internally we like to still think of ourselves as a small company -- a small company working within a very large network of partners. Part of one of the early realizations in the company was that if you’re setting out to create a global standard for a microprocessor, there’s no way you can do everything yourself, and we were going to have to build a strong network of partners in order to be successful. So as well as just licensing our technology to people who were going to build chips containing our processors, we set out to build an ecosystem of companies who would buy support for anybody using an ARM processor. That’s been a very strong part of ARM’s ethos since day one, really. We worked with companies to develop software, to develop software tools, and we worked with EDA companies to make sure there’s support for someone building a chip around an ARM processor, and have generally tried to round out as much technology as we can so that if you’re a design engineer sitting at your desk and saying, “Well I’m going to embed this microprocessor into a chip, what should I use?” It’s kind of a no-brainer to use ARM because there is an industry of people looking to support you and provide you with the other bits and pieces that you need to actually make your product successful. That emphasis on partnership has been the differentiator and a key to our success. We’ve got over 300 licensees and while there’s an overlap in some of what they do, many of them are focused on different markets, in comparison to each other. That’s led to a very wide proliferation of the end applications that ARM is used in, anything from supercomputers at one end of the spectrum, to very low-cost microcontrollers at the other. We’ve focused on building our technology roadmap so that we have an architecture that

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expands all of these different implementation points. We’ve complimented the processes with other technologies such as graphics, software tools, physical IP, so that people can build chips and what we do is provide some of those building blocks, always with an emphasis on power and system efficiency, so that people can then spend their own R&D dollars making chips that are really differentiated from what their competitors do.

How involved does ARM have to be when it comes to manufacturing a process technology of suppliers in relationship to the products they licensed? Increasingly they do. In the early days of ARM what we actually shipped to a customer was a complete layout of a process so that they could drop it into their chip and just have it manufactured. Then through the nineties, chip design moved towards being RTL-based and EDA place and route, and all of that. What the industry did as a whole was create a disconnect between design and manufacturing. I think the industry enjoyed a time when manufacturing was sufficiently abstracted from the design process that you didn’t have to worry about it too much, as long as you weren’t pushing the absolute bounds of performance, which hasn’t been the case for most of the designs, historically, that ARM has gotten into. For about the last 10 years that has changed. People are trying to get more and more performance, they are trying to get lower and lower power -- the sort of free ride that Moore’s Law gave -- smaller feature size, lower cost, lower operating voltage and as a result much lower power. However, those days have kind of come to an end. It’s harder and harder to eke more performance and lower power out of each process technology. We’ve had to become much more intimately involved in that process, and that’s in fact what led to the acquisition

INTERVIEW

of Artisan back in the mid-2000s. There was a realization that that process technology was going to get a lot more complex and for people to get the highest performance and lowest power we couldn’t just ship RTL to people with some scripts, we were going to really have to understand the back-end process and tune what we did to it. What we find ourselves doing today is actually working very closely with the people who develop manufacturing technology. We have close partnerships with TSMC and Samsung, Global Foundries, and IBM—the kind of people who are working on process developments. We run designs on very early flavors of their process in order to get a view and have the opportunity to co-optimize both the process and the IP that’s going to get manufactured in that process. So, when one of our customers comes to do it, we’ve kind of already done it ourselves and they can have the confidence that from our understanding of the process we’re making the right tradeoffs in design, just to get the best out of that process.

As new iterations come out, does the feedback from your licensing partners help drive the specs for the next generation of your products?

“We’ve focused on building our technology roadmap so that we have an architecture that expands all of these different implementation points.”

Yes, they do. It always has been that way. We’ve always operated in a mode where, for new products, we work with a small number, one, two, or three lead partners who are very actively involved in the early stages of design. It works best for us when we’re developing a product with a real customer, who also has a real customer who wants to get a part to market very quickly, and to push the envelope on power, performance, and features. We’ve always worked closely on collaboration with our lead partners in development of our new products, shipping early releases of the Visit: eeweb.com

PULSE “ There are limitless opportunities to couple embedded intelligence with sensing and cloud processing. I think that that has the potential to drive billions of microcontrollers, and hopefully all of those will be ARM based.” product itself, getting them involved with the specification stage, and through the evolution of the product as you actually go through the design stage. That’s been very important. We don’t sit in isolation, trying to invent the next greatest thing possible and then throw it out into the world hope it’s successful. Through that regular feedback from our customers, we hope to get it right -- that’s worked very well for us.

As CEO what will be your focus for the company? It’s about continuing to execute. I think the ARM business model has worked fantastically over the last 23 years, and so a lot of people have asked me what I’m going to do differently. But things are going so well that there is actually no need for any radical change here. What we need to do is make sure we capitalize on some of the opportunities in front of us. Our licensees shipped nearly 9 billion chips last year containing ARM processors, but we see that there is huge potential for higher volumes and new applications for ARM processors to go into. When you look at our conventional markets we’re very well known for being in mobile phones and tablets, and now smartphones, of course. Contrary to what some people believe, I think that that is far from being a saturated market. There’s only about a billion smartphones out there in the world right now -- by about 2020 that should go up to about 5 billion smartphones as much lower-priced devices become available and enable markets in developing countries to really take advantage of this technology. There’s going to be a huge opportunity there, both for the devices themselves and for the impact that that will have on the lives of the people who will get access to this technology and then access to all the information that the internet can offer. Low-cost phones and low-cost tablets are another big opportunity. What all of that is going to do is drive a lot more data; there will be more data being generated and consumed, and that data will need to be moved across networks, both wireless and fixed-wired networks. Over the next decade or so we’ll see a big upgrade in the raw amount of bandwidth around the world, and you will need embedded lowpower processors to make that a reality. We think that ARM is very well suited to take advantage of that growth opportunity.

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Then there’s the cloud, where data is going to get stored, accessed, and processed. When you look at the predictions of how many cloud servers that are going to be deployed over the next few years, it just doesn’t really stack up unfortunately with the amount of electricity that they are going to consume, so we think that there will be a huge opportunity to reshape the way servers that are built. There will be an opportunity get the chips inside servers to be built the same way the mobile phone chips are built, with a very big focus on low-cost power, but also a big focus on integrating a lot more functionality to a SoC. If you start taking a more tailored approach then I think you can save a lot of energy in putting servers together. And given the way that server workloads are changing, I think that opportunity is there. For us there’s a big potential to grow into expanding markets and keep driving our business model forward. That’s the primary part of my job.

Do you see yourself competing with the more traditional large processors and those higher-end PC markets? Well, the good thing about our business model is that we don’t dictate to our licensees about what market they should go into and where they should spend their time. If we take servers for example, that’s an area that’s kind of evolved as an opportunity and many of our licensees have looked at that and seen potential for them to drive their business around selling chips into that market, and the whole thing has kind of taken off. I think that the kind of levels of performance that we’re providing in our processors means that people who can build laptops and desktop systems around ARM technology. As that market changes over time, we’ll see if our licensees want to have a big push into that space. I think that as far as what we do, our focus is on high performance and low power -low power being really important to everything we do. We’re looking at application areas and trying to provide a scalable solution

INTERVIEW

that allows someone to scale the amount of compute power that they provide in their chip, but to do that at the lowest electricity power consumption. So if you’re building a microcontroller, you’ve got access to a very small, very power-efficient processor core. If you’re trying to build a server chip, you’ve got access to a processor that can be scaled up and put down in a multi-core configuration to provide lots of performance--obviously not low-power, but power optimized for that kind of compute performance.

How will the Internet of Things affect your business? The Internet of Things has a lot of potential. With processors becoming small and very low power, and with processor technology becoming very inexpensive, I think it does give the capability to put an embedded processor with a sensor and some form of wireless networking into pretty much anything that would benefit from it. I think that’s going to put many more internet-connected leafnodes out there over the next ten years or so. That could become really interesting. Putting sensors in the road, putting sensors in streetlights, through buildings that we work in is going to provide a huge opportunity to collect data, to process that and extract information from it in the cloud, and then provide that information back to people on their mobile devices to enable them to go about their day in a more-efficient way. Some examples of this are gathering traffic information, finding out what the weather is going to do, or whether it’s simply sensing that your crops in a field 5 miles away is going to get automatically irrigated because the moisture in the soil has been detected. There’s almost limitless opportunity to couple embedded intelligence with sensing and cloud processing. I think that that has the potential to drive billions of microcontrollers, and hopefully all of those will be ARM based. It’s a very interesting space. I think the hardware side of that is interesting, I think the ser-

vices that that could open up over time are also very interesting. It’s a market that we look at with a lot of interest.

Can you talk a little bit about the new architecture that you recently launched? We launched really four products that together are targeted midrange smartphones. Ordinarily you look at Smartphones which are not really part of any market, and the world becomes obsessed with the higher-end, which tends to be relatively low in volume. When we look at smartphones we tend to see the market split into three: very low-cost, entry-level devices, high-cost devices, and in the middle a mid-range, which could be five hundred or six hundred million units out over the next few years. In that mid-range, which is probably going to be largest part of the smartphone market in five years’ time, you need very good performance. You might not need the absolute top end of performance, but you need very low cost and very low power consumption. The Cortex A12, which we announced, is a processor that’s been designed around that sweet spot of great performance, but not spending a whole load of transistors to provide every last ounce of performance, but designed around power consumption. Alongside the Cortex A12 we announced a new graphics processor and a new video processor as well. In parallel we announced some interconnect technology that allows these complex processes to be put together on a chip and the data bandwidth across the chip to be managed and the systems to be put together in a very effective way. So we’re looking at a fairly broad solution to the computing component of a chip that would target this sort of market. We never go as far as building complete reference designs and dictate to the world what they should build and how they should build it, but we provide a collection of components that are designed to work together in a very efficient way, and that’s what the Cortex A12, the Graphics Core, Video, and interconnect technology were all designed to do. We’re delivering those altogether allows a licensee to take those and put a chip together quickly.

What is the ARM Tech Comm? Each year in October we have a big user conference called the ARM Tech Comm. That’s typically around Halloween week at the Santa Clara Convention Center, so if people want to see more of what kind of support the industry offers for doing design around ARM processors, that’s an excellent show piece for what’s going on in a broad way. We’ve had semiconductor companies, we’ve had foundries, we’ve had third parties software developers and operating system people -- the whole spectrum of the ARM ecosystem is represented there. ■

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PULSE Tiny CMOS Real-Time Clock The PCF85063TP is a CMOS Real-Time Clock (RTC) and calendar optimized for low power consumption. An offset register allows fine-tuning of the clock. All addresses and data are transferred serially via the two-line bidirectional I²C-bus. Maximum bus speed is 400 kbit/s. The register address is incremented automatically after each written or read data byte. The device also provides year, month, day, weekday, hours, minutes, and seconds based on a 32.768 kHz quartz crystal...Read More

LTE Triple-Mode Baseband Processor Renesas Electronics Corporation and its subsidiary, Renesas Mobile Corporation announced the availability of its LTE triple-mode modem platform, the SP2531, which integrates a single-chip triple-mode modem baseband processor that supports LTE/ HSPA+/GSM, RF transceiver ICs, high power amplifiers, power management devices and related software. The LTE triple-mode modem platform is targeted at the convergence market which demands high performance...Read More

Precise OFN Modules Optical Finger Navigation (OFN) products from Avago Technologies offer a compact, precise, fast speed and highly reliable navigation solution, which will help enhance the overall system performance. Our OFN solution is user friendly and can be used in electronic devices such as mobile phones, MP3 players, ultra-miniature PCs, game pads, digital cameras and keyboards. The ADBM-A350 OFN Module is a small form factor LED illuminated optical finger navigation system...Read More

4 Lane PCI Express Repeater The DS80PCI402 is a low power, 4 lane repeater with 4-stage input equalization, and output de-emphasis driver to enhance the reach of PCI express serial links in boardto-board or cable interconnects. Ideal for x4 (or lower) PCI express configuration, the DS80PCI402 automatically detects and adapts to Gen-1, Gen-2 and Gen-3 data rates for easy system upgrade. The programmable settings can be applied easily via pins, software (SMBus/I2C) or loaded via an external EEPROM...Read More

1-Wire Thermocouple-to-Digital Converter Maxim Integrated Products, Inc. announced that it is now sampling the MAX31850/ MAX31851 cold-junction-compensated, 1-Wire® thermocouple-to-digital converters. The devices achieve ±2.0°C accuracy (not including sensor nonlinearity) while integrating all of the functions required for a complete thermocouple-to-digital solution. Additionally, the MAX31850/MAX31851’s 1-Wire interface allows multiple sensor locations to communicate and draw power over a single data line, greatly simplifying wiring requirements...Read More

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FEATURED PRODUCTS ARM Cortex-Based Bridge SoC Fujitsu Semiconductor America introduced an Interface Bridge SoC that incorporates 10 different interfaces, more than any other similar single device. Designed for advanced Wi-Fi television tuner applications, the new MB86E631 combines a dual-core ARM® Cortex™-A9 processor and multiple interfaces, including USB 2.0, USB 3.0, Serial ATA, PCI Express, Ethernet MAC, transport stream (TS), and two memory interfaces — all on one SoC. The MB86E631 is designed for equipment such as video-recording devices and TVs with built-in recording capabilities that transmit programming to other devices. The device manages the Wi-Fi TV tuner, which wirelessly sends transcoded H.264 / MPEG-2 streams to storage devices and mobile products such as smartphones and tablets...Read More

Quad High-Voltage Switch Array Clare, Inc., a subsidiary of IXYS Corporation, announced the availability of the CPC7514Z Quad High-Voltage Isolated Analog Switch Array for use in industrial controls, instrumentation, automatic test equipment and telecom applications. The CPC7514Z ICs feature four independently controlled, 320V bidirectional normally open (1-Form-A) relays actuated by latched TTL logic-level control signals. The monolithic silicon, which features high voltage DMOS structures and low voltage CMOS circuitry, is biased by a 3.3V power supply eliminating the requirement for external high-voltage supplies for proper operation...Read More

Synchronous Buck Regulator The ISL70001ASEH is a radiation hardened and SEE hardened high efficiency monolithic synchronous buck regulator with integrated MOSFETs. This single chip power solution operates over an input voltage range of 3V to 5.5V and provides a tightly regulated output voltage that is externally adjustable from 0.8V to ~85% of the input voltage. Output load current capacity is 6A for TJ < +145°C. The ISL70001ASEH incorporates fault protection for the regulator...Read More

Extended Power Range Switcher TOPSwitch-HX incorporates a 700 V power MOSFET, high voltage switched current source, PWM control, oscillator, thermal shutdown circuit, fault protection and other control circuitry onto a monolithic device. TOPSwitch-HX is an integrated switched mode power supply chip that converts a current at the control input to a duty cycle at the open drain output of a high voltage power MOSFET. During normal operation the duty cycle of the power MOSFET decreases linearly with increasing control pin current...Read More

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PULSE 8-Bit CMOS MCU The PIC16F785 Flash microcontroller offers all of the advantages of the well recognized mid-range x14 architecture with standardized features including a wide operating voltage of 2.0-5.5 volts, on-board EEPROM Data Memory, and nanoWatt Technology. Analog peripherals include up to 12 channels of 10-bit A/D, 2 Operation Amplifiers, 2 high-speed analog Comparators, and a Bandgap Voltage Reference. Digital peripherals include a standard Capture/Compare/PWM (CCP) module, a 2-phase PWM with asynchronous feedback, a 16-bit timer and 2 8-bit timers...Read More

Electric Potential Integrated Circuit Sensors Mouser Electronics, Inc. is now globally distributing Plessey Semiconductors’ complete range of innovative products, including Plessey’s multi award-winning EPIC™ sensor and MAGIC GaN LEDs. Mouser’s stocked product offering includes various sensors, such as Plessey’s award-winning EPIC sensors that can be used in contact mode for measuring bio-electric signals like ECG, EMG, EOG and EEG, or in non-contact mode for measuring disruptions in the electric field caused by human body movement...Read More

Absolute Integrated Pressure Sensor The MLX90807 is a fully integrated relative pressure sensor realized with standard CMOS technology in combination with MEMS bulk micromachining. This monolithic solution is fully automotive qualified. Piezoresistors in a wheatstone bridge configuration are placed on the edges of a silicon membrane and transform the stress induced by the pressure on the membrane into an electrical signal. An analog chain interacting with a digital core performs the conditioning of the piezoresistors output voltage. By writing calibration settings in the chip memory a uniform transfer function is obtained over the working pressure and temperature range...Read More

Subminiature Radial Leaded Fuse The 262/268/269 Series are high–reliability micro fuses, with a 125V rating, very fast-acting type with high breaking capacity. This series is listed under the Department of Defense Quality Product List. The product offers protection of electrical, electronic, and communication equipment having printed circuit boards usable in direct current and alternating current circuits capable of withsstanding and functioning in extreme conditions...Read More

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FEATURED PRODUCTS Dual-Mode Wireless Power Receiver IC Integrated Device Technology, Inc. announced the industry’s first dual-mode wireless power receiver IC that provides compatibility with both the Wireless Power Consortium (WPC) and Power Matters Alliance (PMA) standards. IDT’s innovative receiver bridges the technology gap between competing transmission standards, empowering mobile device and accessory OEMs to use a single bill-of-materials (BOM) to support both WPC and PMA standards. The IDTP9021 is ideal for use in a myriad of mobile devices, including smart phones, tablets, MIDs, digital cameras, MP3 players, remote controls, portable medical devices, and other personal electronics...Read More

Smallest Infrared Sensor Element IR1011 is the world smallest mid-infrared quantum photo diode, made of InSb. Considering dimensions as small as 2.65mm×1.9mm×0.4mm, the device is a surface mount type sensor that can be operated at room temperature. AKM’s IR1011 Infrared Sensor does not require any bias current to establish proper operating condition. The device is highly sensitive and has very fast response. IR1011 is applicable to human body detection, non-contacting temperature measurement, and NDIR gas sensor...Read More

Off-Line LED Driver IC Allegro MicroSystems, Inc. announces the release of a new simple and efficient family of LED driver ICs that can be configured as buck or buck-boost voltage converters. The LC5220D/S LED series is offered by Allegro and manufactured and developed by Sanken Electric Co., Ltd. in Japan. This new series is targeted at the consumer market with end applications to include LED lighting fixtures and LED light bulbs. These non-isolating devices operate off-line, having a high voltage capacity that allows direct connection to a wide range of supply voltages...Read More

Full-SiC Power Module An original electric field mitigation structure, along with a novel screening method, are utilized to maintain reliability and enable the development of the first mass production system for Full-SiC power modules. These new modules integrate SiC SBDs and MOSFETs, making high frequency operation above 100kHz possible (unlike conventional products). In addition,high-speed switching, combined with low-loss performance, make them ideal as replacements for 200-400A Si IGBTs. Replacing Si IGBTs with SiC MOSFETs result in the industry’s first mass production of “Full SiC” power modules. ROHM produces both SiC SBDs and SiC MOSFETs in-house, ensuring unparalleled reliability...Read More Visit: eeweb.com

PULSE

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FEATURED ARTICLE

Bluetooth for Digital Audio Like Wi-Fi, Bluetooth is another burgeoning technology in the embedded-wireless arena. Prior to the Roving Network acquisition, Microchip did not have any in-house Bluetooth solutions. With the acquisition, Microchip also acquired some data modules as well as the new RN52, which is their Bluetooth audio module. At the DESIGN West show in April, the company detailed that they were leveraging their PIC32 high-end microcontroller portfolio to do a Bluetoothenabled digital audio development platform. One of the benefits of the entire portfolio of Microchip’s Wi-Fi and Bluetooth modules is that they have gone through all of the agencycertified regulation testing, so that the customers don’t have to deal with that side of development.

MiWi: The Proprietary Protocol MiWi is Microchip’s own proprietary communication protocol. At the show, the company announced its latest 802.15.4 transceiver IC, which is tailored for their ZigBee protocol stack as well as the MiWi proprietary communication protocol. This new transceiver is ideally suited for low-power, low-data-rate, and battery-operated applications, with an operating voltage of as low as 1.5 volts.

PIC32 Bluetooth Audio Development Kit

With this recent RF portfolio expansion announcement, Microchip is poised to take a dominant role in the embedded-wireless space. The company has been expanding not only through acquisitions, but through internal development. Many of these new advanced generation products will serve huge industry trends, such as the predominance of Wi-Fi and the Internet of Things, or the broader “Connectivity of Things” that includes the many forms of wireless connectivity that don’t involve Internet access. According to Smith, this broad offering of RF products shows that Microchip is, “able to meet the needs of the ever growing requirements for wireless in the embedded market.” ■

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Get the Datasheet and Order Samples http://www.intersil.com

Power Factor Correction Controllers ISL6730A, ISL6730B, ISL6730C, ISL6730D The ISL6730A, ISL6730B, ISL6730C, ISL6730D are active Features power factor correction (PFC) controller ICs that use a boost topology. (ISL6730B, ISL6730C, ISL6730D are Coming Soon.) The controllers are suitable for AC/DC power systems, up to 2kW and over the universal line input.

The ISL6730A, ISL6730B, ISL6730C, ISL6730D are operated in continuous current mode. Accurate input current shaping is achieved with a current error amplifier. A patent pending breakthrough negative capacitance technology minimizes zero crossing distortion and reduces the magnetic components size. The small external components result in a low cost design without sacrificing performance. The internally clamped 12.5V gate driver delivers 1.5A peak current to the external power MOSFET. The ISL6730A, ISL6730B, ISL6730C, ISL6730D provide a highly reliable system that is fully protected. Protection features include cycle-by-cycle overcurrent, over power limit, over-temperature, input brownout, output overvoltage and undervoltage protection.

• Reduce component size requirements - Enables smaller, thinner AC/DC adapters - Choke and cap size can be reduced by 66% - Lower cost of materials • Excellent power factor over line and load regulation - Internal current compensation - CCM Mode with Patent pending IP for smaller EMI filter • Better light load efficiency - Automatic pulse skipping - Programmable or automatic shutdown • High reliable design - Cycle-by-cycle current limit - Input average power limit - OVP and OTP protection - Input brownout protection

The ISL6730A, ISL6730B provide excellent power efficiency and transitions into a power saving skip mode during light load conditions, thus improving efficiency automatically. The ISL6730A, ISL6730B, ISL6730C, ISL6730D can be shut down by pulling the FB pin below 0.5V or grounding the BO pin. The ISL6730C, ISL6730D have no skip mode.

• Small 10 Ld MSOP package

Two switching frequency options are provided. The ISL6730B, ISL6730D switch at 62kHz, and the ISL6730A, ISL6730C switch at 124kHz.

• TV AC/DC power supply

• Desktop computer AC/DC adaptor • Laptop computer AC/DC adaptor • AC/DC brick converters

100

VLINE

Applications

VOUT

EFFICIENCY (%)

VCC ISEN

GATE

ICOMP

GND

ISL6730

VIN

ISL6730A, SKIP

80 ISL6730C

75 70

COMP BO

VREG

FIGURE 1. TYPICAL APPLICATION

40 60 OUTPUT POWER (W)

100

FIGURE 2. PFC EFFICIENCY

TABLE 1. KEY DIFFERENCES IN FAMILY OF ISL6730

February 26, 2013 FN8258.0

VERSION

ISL6730A

ISL6730B

ISL6730C

ISL6730D

Switching Frequency

124kHz

62kHz

124kHz

62kHz

Skip Mode

Yes-Fixed

Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2013 All Rights Reserved. All other trademarks mentioned are the property of their respective owners.

Technology You Can Trust

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optocouplers deliver outstanding performance on essential safety and deliver exceptional High Voltage protection for your equipment. Alternative isolation technologies such as ADI’s magnetic or TI’s capacitive isolators do not deliver anywhere near the high voltage insulation protection or noise isolation capabilities that optocouplers deliver. For more details on this subject, read our white paper at: www.avagoresponsecenter.com/672

PULSE

Every piece of information on your

Rob Riemen Computer Engineering Student at the University of Cincinnati

computer is stored somewhere, and there are two types of computer storage. There is Primary storage, such as memory, Random Access Memory (RAM), and Read-Only Memory (ROM). Then there is secondary storage. This is the storage that most people think of when referring to the topic. Data is stored long-term on a hard drive, flash drive, and/ or CDâ&#x20AC;&#x2122;s, in order to revisit the data later. There are a variety of ways to store data in large quantities, but for the sake of this discussion, we will focus on Hard disk drives (HDD).

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TECH ARTICLE

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PULSE

ard disk drives hold most of the stored data of the computer. Every time you save a file, download a song, even move an icon on the desktop, this information is stored somewhere on the hard drive. Even installing an operating system requires a hard drive to store the data the operating system needs to function. Because of this, the hard drive is a key component in building a computer, and when you’re choosing a hard drive, you’ll want to ask yourself a few basic questions. How much space will you need to hold everything that you plan to save on the computer, and then some? How fast do you want to be able to access that information? You should be asking these questions in order to choose a hard drive for your computer because no matter how fast your processor is, how quick memory can store and relay information, or how much rendering your graphics card can do, if you can’t access the information that is stored on the computer, then there is no use for other components. Being able to store large amounts of data and access it quickly make up the main functions of a hard drive. There are actually two separate components of accessing data that make a hard disk drive unique, including data connection type and the rated rotations per minute (RPM). These two components, as well as storage capacity, make up the key characteristics that matter when analyzing a hard drive.

Data Connection Type Hard Drives do not sit in your computer and transfer data wirelessly. The Hard Disk Drive (HDD) has to be physically connected to the computer in some way. This connection type has slowly advanced over the years and now can transfer data at extremely high speeds between the computer and the hard drive. There are several types of connections that are common among most HDDs. The first standard of HDD connections was the AT Attachment (ATA) which was approved in 1994. More commonly known as the Parallel ATA (PATA) connection, it was the standard for HDD connections for over ten years. It was the main connection for storage based devices such as floppy disk drives, optical drives and HDD during this time. Because the maximum length of PATA cables was 18’’ long, PATA was mainly used as an internal connection for HDD’s. It provided 16 bits of information transfer between the hard drive and the rest of the computer. These 16 bits of information were transferred through a wire that contained 40 pins. That made it a rather wide a cumbersome connection. In 2003, a new connection entered the market that made the connection between the hard drive and the computer much faster. The Serial ATA (SATA) connection was established. This connection type established a cheaper and faster connection through native hot swapping and signaling rates. Today, there are two standard in connection types, one for external HDDs and internal HDDs. The standard for external HDD’s is USB, which isn’t used much for internal connections between the HDD and the motherboard. For internal HDDs the SATA is standard. You shouldfigure out the transfer rate of the HDD using a USB connection or SATA connection.

Rotations Per Minute (RPM)

PATA Connector (Courtesy of Wikimedia User D-Kuru)

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The main distinguishing factor of an HDD compared to other hard drives is the fact that an HDD has rotating disks. These disks are continuously spinning at a rapid rate and are manufactured to be coated with magnetic material. As these disks are spinning, a moving actuator arm is moving back and forth across a specific disk. This arm is reading and writing

TECH ARTICLE data to these platters through magnetism. To be more specific, the drive uses ferromagnetic material. This material is magnetized by the actuator arm and the direction in which the disk is magnetized determines how the data is represented in binary. The data is read by the drive through detection of the changes in magnetization. Because of this setup, the disks have to spin at a certain rate. Usually the higher the rate, the faster the disk can read the data. For many years the average speed of HDDs was 3,600 RPM. But because of recent developments and the capacity for larger hard drives, the speed of HDDs has increased. The average speed of drives today hovers between 5,400 and 7,200 RPM. Sometimes in order to access data at the most efficient rate, however, HDDs increase their platter rotation speed to 15,000 RPM. This allows for the fastest access of information across the magnetic platters. The price for HDDs increases exponentially as the speed of rotation increases, however, and with further developments in hard drives in general (outside of HDDs) there is really no benefit in purchasing a HDD with higher RPM than 7,200. This is the standard for HDDs in modern computers and provides sufficient speed for normal users. Make sure to pay special attention to the RPM of the drive as it can determine the difference when accessing your most important files.

Storage Capacity

Now, storage capacity can be a no-brainier. The size of a hard drive is very important to the selection of a hard drive, but sometimes bigger is not always better. In relation the previous argument of RPM, the RPM makes a difference in the access speed of all drives. A one terabyte (TB) drive will access data at the same speed as a 500 gigabyte (GB) drive. The only difference between the two is that the 1 TB drive will have more information that can be accessed as compared to the 500 GB Drive.

Hard Drive Setup (Courtesy of Wikimedia User Surachit)

Conclusion When selecting a hard drive for your computer, make sure to take a few things into consideration. The connection interface is very important in the selection. SATA is the modern connection for HDDs and can transfer data at a much faster rate than PATA HDDs. The RPM of a HDD is very important in getting the most out of a HDD. The faster the platters spin, the more efficient the HDD can transfer data to the computer. A 15,000 RPM hard drive is generally unreasonable with the HDDs that are available today, but 7,200 RPM should provide sufficient speed for the average to above average user. Hard drive storage space is crucial when selection the best storage device for your computer. In general, the higher the capacity, the better the HDD can perform. Regardless of the connection type and the platter speed, data will always be stored on your HDD. If you play video games, edit video, or store large amounts of music--the larger the HDD space, the better. â&#x2013;

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In my experience, the more space the better, although the space of a hard drive is totally based on individual preference. The more information you have to store, the larger the hard drive you will need. 500MB to 1TB of space on a hard drive is acceptable for todayâ&#x20AC;&#x2122;s demanding applications. Visit: eeweb.com

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