Comparison of Embedded Processor Families
Posted by Embedded Board in TI SoC and Microprocessors on February 1, 2012
Microprocessors designed for embedded systems offer limited processing power and features compared to the processors for computers. Microprocessors can be divided in to two types; RISC (Reduced instruction set computing) and, the opposite of it, CISC (Complex instruction set computing). Microprocessors for embedded systems are based on RISC mostly because RISC chips require far fewer transistors to perform the core logic compared to the CISC architecture. Smaller circuitry results in lesser area and energy consumption and this is the reason for the popularity and domination of RISC microprocessors in mobile and embedded devices market. Some of the top microprocessor families for embedded systems will be discussed here.
ARM Microprocessors
ARM (Advanced RISC Machine) is the most popular family of microprocessors in embedded systems market, based on the RISC instruction set architecture. Approximately 90% of all embedded 32-bit RISC processors belongs to the ARM family. Widely used ARM processor families are the ARM7, ARM9, ARM11 and Cortex, with ARM7TDMI being the most popular. The heart of Apple products, the A4 and A5 processors are also based on the ARM core. ARM family is basically 32-bit but there is also one other ARM architecture, known as Thumb, which supports 16-bit instructions. ARM microprocessors can perform multiple operations simultaneously due to the usage of multi stage pipelining and thus improving the processing speed. ARM microprocessors also offer rapid context switching as they have separate register banks for each mode of operation.
Texas Instruments bases many of their System on Chips on ARM architecture: OMAP4460, AM3517, DM3730, AM3703, AM3505. All the chips are based on ARM Cortex A-8, expect for the OMAP4460, which is designed over ARM Cortex A-9.
PowerPC
Another widely used RISC based embedded processor family is the PowerPC which was created jointly by IBM, Motorola and Apple. PowerPC architecture is an open standard and is based on IBM’s earlier POWER architecture. PowerPC family was actually designed for desktop computers and had been used considerably in Apple Macintosh computers, but they have also achieved popularity in embedded systems market. This is evident by the division of operating systems supported on PowerPC that some of them work on PowerPC based desktop computers and some work on PowerPC based embedded systems.
MIPS
MIPS, formerly an acronym for Microprocessor without Interlocked Pipeline Stages, is also a RISC based 32- & 64-bit microprocessor family for embedded systems. MIPS is one of the first RISC architecture based processor families. It is not that famous as the ARM and PowerPC families but still has a good presence in networking equipments market like routers and residential gateways. Embedded MIPS processors have very low power consumption. MIPS I, MIPS II, MIPS III, MIPS IV, MIPS V, MIPS32, and MIPS64, all are instruction sets for MIPS family.
System on Chip (SoC) Manufacturers – A Quick Overview
Posted by Embedded Board in Embedded Development, TI SoC and Microprocessors on January 2, 2012
The global technology strive to converge most of any device’s functionality and hardware on a single chip. Some of the reasons for this are achieving smaller, lighter and energy efficient hardware and faster development speeds. When all or most of the components of a system are embedded or integrated into a single chip, the resulting product is a system-on-chip (SoC). SoC’s are used to simplify complex system designs, and have applications primarily in embedded systems due to the need for diminished size and high processing power and funcionality. Today’s SoC’s are capable enough to run software like Windows and Linux operating systems and some can even perform better than a decade old computer. Sometimes, specialized SoC’s are called by their application name like meter-on-chip and base station-on-chip. Few of SoC manufacturers are discussed here.
Texas Instruments (TI) is one of the top SoC manufacturers and is mostly ARM architecture focused. OMAP is a famous line of ARM based SoC’s from TI which is geared towards mobile multimedia applications and is divided into high performance, basic and integrated application processors. TI has developed different SoC’s for many different applications like data acquisition, media and telecommunication. TI’s analog-to-digital converter (ADC) front ends SoC’s are widely used for precision data acquisition and metering applications. For multimedia applications, OMAP4 line offers improved PowerVR SGX544 based graphic cores. TI is also working on introducing mobile carrier application SoC’s, called base station-on-chip, to improve performance of mobile communication hardware, covering smaller area usually termed as Microcells or Femtocells.
Freescale, another major SoC manufacturer, holds approximately 6,100 patent families. Freescale SoC’s are mostly targeted to communication applications. Many Freescale SoC’s are based on the “Power Architecture”, for example, Freescale’s e300, e500, e600 and e700 SoC’s. Other Power architecture based SoC family from Freescale is PowerQUICC for use in embedded networking equipment applications. Freescale has also introduced SoC’s for multimedia applications like the i.MX53 family based on ARM Cortex-A8 core. Like Texas Instruments, Freescale is also developing base station-on-chip SoC’s, named QorIQ Qonverge, for mobile carrier hardware and base station transceivers (BTS). Freescale has developed designs of meter-on-chip SoC’s for smart meter applications which integrate most of the smart meter functions into a single chip.
Marvell Technology Group is another company that develops SoC’s. One of their popular ARM based SoC line is “Orion” which has applications in networked storage. Marvell also produces award winning media processor SoC’s called ARMADA which is used in multimedia players, HD TV’s and set top boxes (STB). NXP (by Philips) is one of the largest semiconductor product manufacturers which also develops SoC’s. NXP SoC’s are targeted to energy, telecommunication and multimedia applications, for example, the EM773 and JN5148 SoC’s from NXP.
AM3505 – TI’s sitara family microprocessor
Posted by Embedded Board in TI SoC and Microprocessors on December 21, 2011
AM3505 Overview
The AM3505 of Texas Instruments (TI) is a sister microprocessor of AM3517, both belonging to the Sitara family of ARM core based microprocessor units (MPU’s). Both AM3505 and AM3517 are similar except for the absence of an OpenGL graphics engine subsystem in AM3505 which is used for 3D graphics acceleration suitable for gaming applications. AM3505 and AM3517 were released by TI primarily to target industrial applications but both have also found good use in average consumer applications as well ranging from personal handheld multimedia & data management gadgets like smartphones, to large scale home & commercial automation solutions.
AM3505 block diagram (source: ti.com)
With power consumption of less than 1 milli Watt, AM3505 can be used in battery powered portable products. Like the AM3517, AM3505 is also based on the ARM Cortex A8 core which offers a considerable performance advantage over the ARM9 core which is used in other Sitara family MPU’s. This microprocessor is architecturally similar to the OMAP35xx application processors from TI except of the absence of a digital signal processor (DSP) module for HD (high definition) quality video processing. Despite the absence of a DSP, it is capable of processing HD video signals but with limited functionality. As mentioned above, 3D graphics processing module is also absent in this microprocessor, hence unable to produce same quality effects and visuals as possible through AM3517. Apart from this, AM3505 offers many other video related processing features like multiple concurrent image manipulation which is commonly known as “picture in picture”. Although it may be a disadvantage for not providing a DSP and the graphics accelerator subsystem, it is affects the cost reduction of chip which is further decreased by the usage of DDR2 memory in this MPU. This might trade off this disadvantage in the eyes of some electrical engineers.
Due to its target market, AM 3505 comes with industry focused connectivity features like PHY (physical layer) functionality in USB On The Go (OTG), dual USB host, an advanced CAN controller and EMAC. Major requirements for devices with industry targeted applications are the ruggedness and endurance against temperature and mechanical extremes of an industrial environment, to which it complies. AM3505 has usage mostly in applications requiring video displays because of the presence of its vast array of video signal capture and output features, making it an appropriate choice for embedded systems requiring a HMI (Human Machine Interface) or information and entertainment video output. AM3505 offers lots of peripherals and connectivity interfaces some of which include different types of timers, multiple serial ports, interfaces for removable storage media like SD card, 186 general purpose input output (GPIO) pins for customized application circuitry, JTAG test interface, etc. All major high level and real time operating systems like Linux, Windows Embedded & CE and Android, are supported by the AM3505.
Embedded Development Books
Posted by Embedded Board in Embedded Development on December 15, 2011
Embedded development books – overview and recommendations
Embedded systems come in all shapes and sizes with hardware platforms ranging from a discrete component or digital logic circuit to full scale, high performance microprocessors running advanced, high level operating systems. Development tools, both hardware and software, and programming languages for this large range of embedded systems are also equally vast. This is also the case with the learning material for embedded systems development, especially in the form of books. Here, in this article, only the books related to microprocessor based embedded systems are recommended and discussed, belonging to both aspects, that is the embedded system hardware and software.
Whatever the software or firmware, embedded system is nothing without the embedded hardware itself. “Designing Embedded Hardware”
Software or firmware development books: Microprocessor based systems are usually developed with an operating system based firmware. Major OS’s include Microsoft Windows Embedded or CE and Linux (sometimes called Embedded Linux). Linux is mostly used because of it being free and open source. “Embedded Linux Primer – A Practical, Real-World Approach”
Kernel development is a very important part of porting an embedded operating system for the target application hardware. “Linux Kernel Development”
To start learning real time operating system (RTOS) concepts, “Real-Time Concepts for Embedded Systems”
by Qing Li and Caroline Yao is a good one. As the name suggests, real time operating systems must respond to events or complete their tasks in a very limited time. This books starts from the basics of operating systems (OS) and the difference between a normal (high level) and a real time OS, and takes it to the advanced level.
I hope that I covered that main aspects of embedded development industry. If you come across a worthy book – I’ll be happy to hear about it!
Android 4.0 Development – The New Goodies
Posted by Embedded Board in Embedded Development on December 10, 2011
Android 4.0 (code name “Ice Cream Sandwich”) was officially launched on 19 October 2011 in Galaxy Nexus and Ice Cream Sandwich release event. Let’s go over the main features and improvement that this new version provides us as developers.
In developer’s point of view, the Android 4.0 brings many new features and capabilities and a lot of new APIs. Any Android 4.0 developer will agree on the point that this version has increased performance of applications dramatically. We start with the new connectivity feature Wi-Fi Direct. This allows developers to create applications for sharing data like photos or any other file without the need of wireless access point. This feature in particular enables game developers to add network gaming capability – again without the need of wireless access point.
The Android 4.0 brings a series of new social APIs. The most prominent include Android Beam, which is an exciting new feature which allows two NFC (Near Field Communication) enabled phones to start communication by just touching with each other. This allows developers to make applications to share small data in a new way. For large amount of data this type of connection can initiate Bluetooth connection. Second, is shared calendar content provider and framework API, which provides developers the possibility to use calendar services for their applications (and with the personalization of the various gadgets, this is quite useful).
In addition, the new release provides many new media capabilities, including direct and efficient path for low level streaming multimedia, new camera features like full resolution image capture while capturing video, and new ways of setting white balance and exposure. The support for many new media types and containers like VP8, HTTP Live streaming protocol version 3 and many more give application developer s a lot of flexibility and easiness in developing media related application .
When it comes to UI, Android 4.0 brings a new unified UI for phones, tablets and any Android powered device which was a demanding feature by developers, since it helps to maintain consisting design practices and easiness in code development process. Furthermore, this new UI gives a new layout called grid layout, which has proved to increase performance of applications. Similarly, a new texture view object lets developers directly integrate OpenGL ES textures as rendering targets in a UI hierarchy.
Android 4.0 offers an enhanced accessibility API specially designed for devices which have not hardware buttons. Using a text to speech API the developers can easily write text to speech engines. Earlier Android did not have text to speech API at framework level. This was also a demand by developers to develop text to speech conversion applications easily.
In conclusion, no doubt that Android 4.0 is a major improvement in comparison to the previous versions. This reflects the growth in the needs of the users, especially regarding connectivity and sharing and media handling. It will be interesting to see how the new generation of products and gadgets will look like with the Android ICS. Until then – it’s time to think and imagine how will Android 5.0 will look like!
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