The PCA9671 provides general purpose remote I/O expansion for most microcontrollerfamilies via the two-line bidirectional bus (I2C-bus) and is a part of the Fast-mode Plus(Fm+) family.The PCA9671 is a drop in upgrade for the PCF8575 providing higher I2C-bus speeds(1 MHz versus 400 kHz) so that the output can support PWM dimming of LEDs, higherI2C-bus drive (30 mA versus 3 mA) so that many more devices can be on the bus withoutthe need for bus buffers, higher total package sink capacity (400 mA versus 100 mA) thatsupports having all 25 mA LEDs on at the same time and more device addresses (64versus 8) to allow many more devices on the bus without address conflicts.
The PCA9672 provides general purpose remote I/O expansion for most microcontrollerfamilies via the two-line bidirectional bus (I2C-bus) and is a part of the Fast-mode Plusfamily.The PCA9672 is a drop-in upgrade for the PCF8574 providing higher Fast-mode Plus(Fm+) I2C-bus speeds (1 MHz versus 400 kHz) so that the output can support PWMdimming of LEDs, higher I2C-bus drive (30 mA versus 3 mA) so that many more devicescan be on the bus without the need for bus buffers, higher total package sink capacity(200 mA versus 100 mA) that supports having all LEDs on at the same time and moredevice addresses (16 versus 8) are available to allow many more devices on the buswithout address conflicts.
The PCA9673 provides general purpose remote I/O expansion for most microcontrollerfamilies via the two-line bidirectional bus (I2C-bus) and is a part of the Fast-mode Plusfamily.The PCA9673 is a drop in upgrade for the PCF8575 providing higher Fast-mode Plus(Fm+) I2C-bus speeds (1 MHz versus 400 kHz) so that the output can support PWMdimming of LEDs, higher I2C-bus drive (30 mA versus 3 mA) so that many more devicescan be on the bus without the need for bus buffers, higher total package sink capacity(400 mA versus 100 mA) that supports having all 25 mA LEDs on at the same time andmore device addresses (16 versus 8) are available to allow many more devices on the buswithout address conflicts.
Internal Interrupts are used to respond to asynchronous requests from a certain part of themicrocontroller that needs to be serviced. Each peripheral in the TriCore as well as theBus Control Unit, the Debug Unit, the Peripheral Control Processor (PCP) and the CPUitself can generate an Interrupt Request.So what is an external Interrupt?An external Interrupt is something alike as the internal Interrupt. The difference is that anexternal Interrupt request is caused by an external event. Normally this would be a pulseon Port0 or Port1, but it can be even a signal from the input buffer of the SSC, indicatingthat a service is requested.The User’s Manual does not explain this aspect in detail so this ApNote will explain themost common form of an external Interrupt request. This ApNote will show that there is aneasy way to react on a pulse on Port0 or Port1 and to create with this impulse an InterruptService Request. Later in the second part of the document, you can find hints on how todebounce impulses to enable the use of a simple switch as the input device.Note: You will find additional information on how to setup the Interrupt System in theApNote “First steps through the TriCore Interrupt System” (AP3222xx)1. It would gobeyond the scope of this document to explain this here, but you will find selfexplanatoryexamples later on.
The Infineon TriCore provides an Interrupt System with a high safety standard. Thisdocument contains some instructions on how to initiate an Interrupt from an externaldevice. First it will show you how to trigger an Interrupt Service Request by an impulseon Port 0 or Port 1. Then in the second part of the document you can find hints how todebounce impulses to enable the use of a simple switch as input device.Authors: Thomas Bliem, CQ Nguyen / Infineon SMI MD Apps
The standard that governs the design of avioniccomponents and systems, DO-254, is one of the mostpoorly understood but widely applicable standardsin the avionic industry. While information on thegeneral aspects of the standard is easy to obtain, thedetails of exactly how to implement the standard aresketchy. And once an entity develops a process thatachieves compliance, the details of how compliancewas achieved become part of the intellectualproperty of that entity. This white paper focuses onthe details of developing a DO-254 compliantprocess for the design of FPGAs.
Field Programmable Gate Arrays (FPGAs) are becoming a critical part of every system design. Many vendors offer many different architectures and processes. Which one is right for your design? How do you design one of these so that it works correctly and functions as you expect in your entire system? These are the questions that this paper sets out to answer.
在現(xiàn)代通信系統(tǒng)中，電話語(yǔ)音的頻帶被限制在300 Hz～4 kHz的范圍內(nèi)，帶來(lái)了語(yǔ)音可懂度和自然度的降低。為了在不增加額外成本的前提下提高語(yǔ)音的可懂度和自然度，進(jìn)行了電話語(yǔ)音頻帶擴(kuò)展的研究。提出了一種改進(jìn)的基于碼本映射的語(yǔ)音帶寬擴(kuò)展算法：在碼本映射的過程中，使用加權(quán)系數(shù)來(lái)得到映射碼本。客觀測(cè)試結(jié)果表明，用此算法得到的寬帶語(yǔ)音的譜失真度比用一般的碼本映射降低至少2%。主觀測(cè)試結(jié)果表明，用此算法得到的寬帶語(yǔ)音具有更好的可懂度和自然度。
Abstract:
In modern communication systems， the bandwidth of telephone speech is limited from 300Hz to 4 kHz， which reduces the intelligibility and naturalness of speech. Telephone speech bandwidth extension is researched to get wideband speech and to improve its intelligibility and naturalness， without increasing extra costs. This paper put forward an improved algorithm of speech bandwidth extension based on codebook mapping. In the process of codebook mapping， weighted coefficients were used to get mapping codebook. Objective tests show that spectral distortion of wideband speech obtained by this algorithm reduces at least 2%， comparing to conditional codebook mapping. Subjective tests show that the wideband speech obtained by this algorithm has better intelligibility and naturalness.
The field of microelectromechanical systems (MEMS), particularly micromachinedmechanical transducers, has been expanding over recent years, and the productioncosts of these devices continue to fall. Using materials, fabrication processes, anddesign tools originally developed for the microelectronic circuits industry, newtypes of microengineered device are evolving all the time—many offering numerousadvantages over their traditional counterparts. The electrical properties of siliconhave been well understood for many years, but it is the mechanical properties thathave been exploited in many examples of MEMS. This book may seem slightlyunusual in that it has four editors. However, since we all work together in this fieldwithin the School of Electronics and Computer Science at the University of Southampton,it seemed natural to work together on a project like this. MEMS are nowappearing as part of the syllabus for both undergraduate and postgraduate coursesat many universities, and we hope that this book will complement the teaching thatis taking place in this area.
With the Altera Nios II embedded processor, you as the system designercan accelerate time-critical software algorithms by adding custominstructions to the Nios II processor instruction set. Using custominstructions, you can reduce a complex sequence of standard instructionsto a single instruction implemented in hardware. You can use this featurefor a variety of applications, for example, to optimize software innerloops for digital signal processing (DSP), packet header processing, andcomputation-intensive applications. The Nios II configuration wizard,part of the Quartus® II software’s SOPC Builder, provides a graphicaluser interface (GUI) used to add up to 256 custom instructions to theNios II processor
