An Engineer's Guide to the LPC2100 Series
●7 commentsThis book is intended as a hands-on guide for anyone planning to use the Philips LPC2000 family of microcontrollers in a new design. It is laid out both as a reference book and as a tutorial. It is assumed that you have some experience in programming microcontrollers for embedded systems and are familiar with the C language. The bulk of technical information is spread over the first four chapters, which should be read in order if you are completely new to the LPC2000 and the ARM7 CPU.
Choosing An Ultralow-Power MCU
This application report describes how to compare ultralow-power MCUs. It discusses the key differences between popular low-power MCUs and how to interpret features and specifications and apply them to application requirements
Interrupts, Low Power Modes and Timer A
This document contains a lot of what you need to know to get the most out of the MSP430. The MSP430 line is renowned for it's low power usage, and to really utilize it well you have to architect your software to be an interrupt driven device that utilizes the low power modes.
PID Without a PhD
●8 commentsPID (proportional, integral, derivative) control is not as complicated as it sounds. Follow these simple implementation steps for quick results.
Reed-Solomon Error Correction
[Best paper on Reed-Solomon error correction I have ever read -- and it's from the BBC!] Reed-Solomon error correction has several applications in broadcasting,in particular forming part of the specification for the ETSI digital terrestrial television standard, known as DVB-T. Hardware implementations of coders and decoders for Reed-Solomon error correction are complicated and require some knowledge of the theory of Galois fields on which they are based. This note describes the underlying mathematics and the algorithms used for coding and decoding,with particular emphasis on their realisation in logic circuits. Worked examples are provided to illustrate the processes involved.
Memory allocation in C
●5 commentsThis article is about dynamic memory allocation in C in the context of embedded programming. It describes the process of dynamically allocating memory with visual aids. The article concludes with a practical data communications switch example which includes a sample code in C.
Advanced Linux Programming
●6 commentsThis book is intended for learning advanced linux programming.
Red Hat Linux - The Complete Reference
This book identifies seven major Linux topics: basic setup, environments and applications, the Internet, servers, administration, and network administration. These topics are integrated into the different ways Red Hat presents its distribution: as a desktop workstation, network workstation, server, and development platform
Essential Linux Device Drivers
●5 commentsThis book is about writing Linux device drivers. It covers the design and development of major device classes supported by the kernel, including those I missed during my Linux-on-Watch days. The discussion of each driver family starts by looking at the corresponding technology, moves on to develop a practical example, and ends by looking at relevant kernel source files. Before foraying into the world of device drivers, however, this book introduces you to the kernel and discusses the important features of 2.6 Linux, emphasizing those portions that are of special interest to device driver writers.
CPU Memory - What Every Programmer Should Know About Memory
●6 commentsAs CPU cores become both faster and more numerous, the limiting factor for most programs is now, and will be for some time, memory access. Hardware designers have come up with ever more sophisticated memory handling and acceleration techniques–such as CPU caches–but these cannot work optimally without some help from the programmer. Unfortunately, neither the structure nor the cost of using the memory subsystem of a computer or the caches on CPUs is well understood by most programmers. This paper explains the structure of memory subsystems in use on modern commodity hardware, illustrating why CPU caches were developed, how they work, and what programs should do to achieve optimal performance by utilizing them.
Essential Linux Device Drivers
●5 commentsThis book is about writing Linux device drivers. It covers the design and development of major device classes supported by the kernel, including those I missed during my Linux-on-Watch days. The discussion of each driver family starts by looking at the corresponding technology, moves on to develop a practical example, and ends by looking at relevant kernel source files. Before foraying into the world of device drivers, however, this book introduces you to the kernel and discusses the important features of 2.6 Linux, emphasizing those portions that are of special interest to device driver writers.
Stop Guessing – Trace Visualization for RTOS Firmware Debugging
Some decades ago, the embedded industry shifted focus from assembly to C programming. Faster processors and better compilers allowed for raising the level of abstraction in order to improve development productivity and quality. We are now in the middle of a new major shift in firmware development technology. The increasing use of real-time operating systems (RTOS) represents the third generation of embedded software development. By using an RTOS, you introduce a new abstraction level that enables more complex applications, but not without complications.
Enhanced Sample Rate Mode Measurement Precision
The low-noise system architecture and the tailored frequency response employed in the HDO4000A, HDO6000A, HDO8000A and MDA800A series provides the foundation for enhancing ADC sample rates through additional techniques. In this case, carefully constructed filters combined with a pristine front-end amplifier and a frequency response carefully limited to 1 GHz provide the opportunity to provide more measurement precision than would otherwise be possible. The technique utilized to achieve higher measurement precision is interpolation, and this technique is used by default as an Enhanced Sample Rate up to 10 GS/s. By integrating the Enhanced Sample Rate functionality with the normal Timebase controls for Sample Rate, Time and Acquisition Memory adjustment, the oscilloscopes are optimized for best waveform signal fidelity in all situations.
Electrical Ground Rules Part 3
Best Practices for Grounding Your Electrical Equipment Examining the role of ground as a voltage stabilizer and transient limiter, along with tips on improving safety and signal integrity (Part 3 of 3)
Electrical Ground Rules Part 1
Best Practices for Grounding Your Electrical Equipment A look at circuit grounding and its importance to you, as well as the US AC power system and its use of earth ground (Part 1 of 3)
Driving I2C-Bus Signals Over Twisted Pair Cables with PCA9605
The availability of powerful I2C buffers that drive their I/Os on both sides to a nominal ground or ‘zero offset’ logic level allows the removal of noise introduced into one section of a larger bus system. That ‘regeneration’ of clean I2C signals enables building long I2C buses by combining together relatively short bus sections, each say less than 20 meters, using such buffers or multiplexers that contain them. Conventional twisted pair communication cabling with its convenient connectors, and a ‘modular’ I2C system approach, make large system assembly easy. Each drop point or node can be individually selected for bidirectional data communication with the Master just by using normal I2C software addressing. As an example, a system is described for control of LED lighting displays and it is suggested that the power for the LEDs, and the I2C control system, might be economically provided using ‘extra low voltage’ distribution at 48 V using either the control signal cable or similar low cost wiring in a manner similar to that used in ‘Power over the Ethernet’ systems. The simplicity and flexibility of this approach makes it attractive to consider as an alternative to other control systems such as RS-485 or CAN bus.
Lessons in Electric Circuits - Volume III - Semiconductor
●2 commentsThis book covers all of the common semiconductor devices and their principles of operation. However, the true value of this reference is in the fact that it provides key circuits and applications where they come in handy. A few of the devices that are covered in this book are Bipolar junction transistors, diodes, JFETs, thyristors, OPAMPs and FETs. This book will be a good reference in your library that has a clear style of explanation.
A Guide to Approximations
Most embedded processors don’t know how to compute trig and other complex functions. Programming in C we’re content to call a library routine that does all of the work for us. Unhappily this optimistic approach often fails in real time systems where size, speed and accuracy are all important issues. The compiler’s runtime package is a one-size-fits-all proposition. It gives a reasonable trade-off of speed and precision. But every embedded system is different, with different requirements. In some cases it makes sense to write our own approximation routines. Why?
Topics in Secure Embedded System Design
Pervasive networks have led to widespread use of embedded systems, like cell phones, PDAs, RFIDs etc., in increasingly diverse applications. Many of these embedded system appli- cations handle sensitive data (e.g., credit card information on a mobile phone/PDA) or perform critical functions (e.g., medical devices or automotive electronics), and the use of security protocols is imperative to maintain con dentiality, integrity and authentication of these applications. Typically embedded systems have low computing power and nite energy supply based on a battery, and these factors are at odds with the computationally intensive nature of the cryptographic algorithms underlying many security protocols. In addition, secure embedded systems are vulnerable to attacks, like physical tampering, malware and side-channel attacks. Thus, design of secure embedded systems is guided by the following factors: small form factor, good performance, low energy consumption (and, thus,longer battery life), and robustness to attacks. This thesis presents our work on tackling three issues in the design of secure embedded systems: energy consumption, performance and robustness to side-channel attacks. First, we present our work on optimizing the energy consumption of the widely employed secure sockets layer (SSL) protocol running on an embedded system. We discuss results of energy analysis of various cryptographic algorithms, and the manner in which this information can be used to adapt the operation of SSL protocol to save energy. Next, we present results of our experiments on optimizing the performance of Internet protocol security (IPSec) protocol on an embedded processor. Depending on the mode of operation, the IPSec computation is dominated by cryptographic or non-cryptographic processing. We demonstrate how both these components of the IPSec protocol can be optimized by leveraging the extensible and con gurable features of an embedded processor. Next, we introduce a satisfability-based framework for enabling side-channel attacks on cryptographic software running on an embedded processor. This framework enables us to identify variables in the software implementations which result in the disclosure of the secret key used. Thus, security of software implementations can be improved by better protection of these identified variables. Finally, we conclude by introducing a novel memory integrity checking protocol that has much lower communication complexity than existing Merkle tree-based protocols while incurring a modest price in computation on the processor. This scheme is based on Toeplitz matrices, and can be very efficiently realized on embedded systems with hardware extensions for bit matrix operations.
Boosting Performance Oscilloscope Versatility, Scalability Whitepaper
Rising data communication rates are driving the need for very high-bandwidth real-time oscilloscopes in the range of 60-70 GHz. These instruments are essential for validating and debugging new designs in coherent optical modulation analysis, high energy physics research, high speed data communications and other areas. With the DPO70000SX Performance Oscilloscope series, Tektronix delivers real-time signal acquisition with an ultra-high bandwidth of 70 GHz, along with a real-time sample rate of 200 GS/s (5ps/sample resolution), making it ideal for such applications.
