高性能数字输出音频处理器

TAS3308音频片上系统是一款单芯片SoC，适合如数字电视音频子系统、迷你／微型组合音响、5．1条形音箱等消费类音频电子产品。     

Sigma Designs新型高性能媒体处理器选用MIPS科技IP内核

为数字消费、家庭网络、无线、通信和商业应用提供业界标准架构、处理器及模拟IP的MIPS科技公司近日宣布．其可合成MIPS32^TM内核已为Sigma Designs公司（纳斯达克交易代码：SIGM）新的SMP8644安全媒体处理器采用。多核SMP8644系统级芯片（SoC）专为下一代IPTV机顶盒、IP有线机顶盒、蓝盘播放器等功能丰富的消费类产品而设计，集成了包括超标量体系结构MIPS3274K^TM内核在内的三个MIPS^TM处理器。     

数字技术在音频放大器中的应用——数字处理放大器（1）

一、数字信号处理基础知识模拟音频信号处理系统如图1（a）所示的那样．各种处理电路是串联连接的．进行电平调整,音质调整,频率补偿等各种信号处理,这种处理方法具有在处理过程中都必然会引起线性和信噪比的恶化．只是多少不同而已。     

独立多核音频处理器将得到广泛应用

随着半导体技术的进步,提高集成度成为系统厂商追求的目标。不过在音频领域则可能是一个例外,独立的音频处理器因其更好处理性能或将得到更为广泛的应用。在平板电脑、智能手机等便携消费产品应用中,多核处理器已成为高端产品的标配,而随着用户对高品质声音需求的提高,音频处理也开始采用多核技术。不久前,欧胜微电子发布了业界首款四核高清(HD)音频处理器系统级芯片,目标直指智能手机、平板电脑以及便携多媒体设备,旨在大幅提升这些设备的音频性能,为用户带来更好的音效体验。欧胜微电子全球渠道销售总     

TMS320DM642多媒体处理系统中高性能音频功能的实现

介绍了在以新一代高性能处理器TMS320DM642为核心的多媒体处理系统中,采用音频编解码芯片TLV320AIC23实现高性能音频处理功能,详细说明了TMS320DM642多路音频串口McASP和内置集成电路总线的软硬件接口设计,并给出了TLV320AIC23初始化设置参数。     

用于车载音频设备的ColdFire MCF5251音频处理器

车载信息服务系统和汽车信息娱乐处理器MCF5251符合微软PlaysForSure2．0和PlaysFromDevice规范，是便携式和车载信息娱乐音频应用的理想之选，这些应用包括卫星广播、CD或硬盘（HDD）压缩音频播放器、USB Thumb驱动器播放器、自动唱片点唱机和MP3迷你音乐站。此外，MCF5251还可以实现几小时的音频重放，并拥有足够的电源来驱动MPEG4 QCIF视频重放。     

“放入即用”的完整的音频IP子系统

DesignWare SoundWave Audio Subsystem是用于系统级芯片（SoC）设计的一套完整的、集成化硬件和软件音频IP子系统。该音频子系统完全可配置,并支持具有24位精度的从2．0到7．1声道音频流,以满足诸如数字电视、机顶盒、蓝光光盘播放机、便携音频设备及平板电脑等多样化音频应用的需求。     

MIPS科技的多线程处理器为Mobileye新款C2—270TM防撞系统带来强大功能

为数字消费、家庭网络、无线、通信和商业应用提供业界标准处理器架构与内核的领导厂商美普思科技公司宣布,全球视觉式防撞系统领导厂商Mobileye新近推出的革命性C2—270^TM防撞系统采用了MIPS科技的多线程MIPS32TM34K^TM内核。     

DVB-C发射端信道处理系统的SoPC设计与实现

依据DVB-C协议标准，综合考虑系统性能、集成度和设计风险，在FPCA开发平台上得供了基于Nios嵌入式处理器内核的SoPC（Systent on a Programmable Chip）设计策略，实现了DVB-C发射端信道得系统的高性能，低成本设计。本文主要讨论了相关的软硬件实现以及同步机制，最后完成了系统的板级验证和调试。     

MIPS科技推出可为Mobileye新款C2—270^TM防擅系统带来强大功能的多线程处理器

为数字消费、家庭网络、无线、通信和商业应用提供业界标准处理器架构与内核的领导厂商美普思科技公司宣布．全球视觉式防撞系统领导厂商Mobileye新近推出的革命性C2—270TM防撞系统采用了MIPS科技的多线程MIPS32TM34KTM内核。     

网络应用微处理器的演变

用于控制和包处理的微处理器是现代网络设备的心脏。基于MIPS的64位微处理器应用于接入、城域光网、传输这些从边缘到核心的所有网络领域。但是,要达到更高线路速率和更多功能的双重要求,设计师必须寻找能够提高网络设备处理能力的新系统结构。 通用型微处理器为了帮助满足OC-48线路速率要求和继续成为未来网络结构的可行解决方案,必须提供大幅度改善的包处理性能。举例来说,一些最近面世的微处理器结构具有集成的高速双CPU和专为联网设计的接口。目前,网络元素除作为单个构件而设计外,设计人员正在将微处理器集成到系统结构中,     

用于音频的增强DAC技术

在Δ-∑音频数模传换器(DAC)的基础上采用增强DAC技术可以进一步提高音质。本文对此作了简要介绍，并以Wolfson公司的WM8740芯片为例分析了AC和DC两种扫描测试方法得到的关系曲线。     

Streaming processors for next-generation mobile imaging applications

Next-generation mobile devices will continue to demand high processing power for imaging applications. The expected performance is in the class of supercomputers, but delivered with limited energy and memory bandwidth for embedded systems. This article advocates a streaming computation model that leverages the deterministic access patterns in imaging applications to deliver the necessary processing throughput. A reconfigurable datapath connects a set of functional units, forming a computation pipeline to offer energy efficiency. The architecture and implementation of a stream processor are presented along with the memory subsystem to support stream data transfers. The results show speedup ranging from a factor of 2 to 28 for imaging applications, offering favorable comparison against scalar processors.     

Selective encryption for consumer applications

Selective encryption is a technique to save computational complexity or enable interesting new system functionality by only encrypting a portion of a compressed bitstream while still achieving adequate security. Although suggested in a number of specific cases, selective encryption could be much more widely used in consumer electronic applications ranging from mobile multimedia terminals through digital cameras were it subjected to a more thorough security analysis. We describe selective encryption and develop a simple scaler quantizer example to demonstrate the power of the concept, list a number of potential consumer electronics applications, and then describe an appropriate method for developing and analyzing selective encryption for particular compression algorithms. We summarize results from application of this method to the MPEG-2 video compression algorithm.     

Low-consumption sigma-delta DAC for audio mobile applications

A new three-level D-to-A sigma?delta converter for low consumption applications is presented. The two one-bit outputs of this converter can drive a loudspeaker directly without requiring passive components and with a sufficient audio quality. The global consumption is minimised by reducing the number of active states.     

The benefits of interdisciplinary scenario-building for hybrid radio applications

In this paper, we make the case for building interdisciplinary scenarios, integrating technological, business and user perspective during the fuzzy front-end of innovation. We start from a living lab framework, underpinning the iterative process to integrate insights from all three perspectives within research projects. Then, we explain how the approach was applied within the HRADIO project¹. This EU funded project focuses on the development of hybrid radio applications. We demonstrate how the process of building interdisciplinary scenarios and the involvement of multiple perspectives to evaluate these scenarios, has enabled both strategic decision making (1) and improved the technical development process within the HRADIO project (2). The first focuses on the (lack of) interest in certain scenarios from a business, technology and/or user perspective, to explain: (a) how these thresholds can be overcome and (b) what the consequences are for the project. The latter explains how we moved from interdisciplinary scenarios to a first Minimum Viable Product (MVP) that could be tested in the first pilot phase, to prototypes to be tested in the second pilot phase. To validate the importance of the scenarios, we also explain how the scenarios are integrated into the exploitation timeline. Finally, and importantly, we address how the process of multidisciplinary scenario building and evaluation can be improved.     

A current-mode power sigma-delta modulator for audio applications

Linear and switching techniques are currently adopted to implement current-mode power stages. Pulsewidth modulation (PWM) is usually employed with the switching technique for both industrial and audio applications. In this paper, the Sigma-Delta modulation is considered as an alternative to the PWM in devising a switching current-mode power stage suitable for audio amplification. The proposed modulator is analyzed and simulated. The whole system was realized on an experimental breadboard. The results carried out on the prototype are reported and discussed. The electrical characterization presents interesting features in terms of linearity, noise, and power efficiency.     

A fourth-order bandwidth-reconfigurable delta-sigma modulator for audio applications

正A single loop fourth-order delta-sigma modulator is presented for audio applications.A reconfigurable mechanism is adopted for two bandwidth-based modes(8 kHz/16 kHz).Manufactured in the SMIC 0.13μm CMOS mixed signal process,the chip consumes low power(153.6μW) and occupies a core area of 0.98×0.46 mm~2.The presented modulator achieves an 89.3 dB SNR and 90.2 dB dynamic range in 16 kHz mode,as well as a 90.2 dB SNR and 86 dB dynamic range in 8 kHz mode.The designed modulator shows a very competitive figure of merit among state-of-the-art low voltage modulators.     

基于音频应用的四阶带宽可重构的Delta Sigma调制器

本文提出一种应用于音频领域的单环四阶Delta Sigma调制器,采用可重构机制以适用于两种基于带宽的模式（8kHz/16kHz）。该芯片采用SMIC 0.13μm CMOS 混合信号工艺,功耗为153.6μW,占用面积0.98*0.46mm2。该调制器在16kHz模式下,性能达到89.3dB的信噪比（SNR）和90.2dB的动态范围（DR）;在8kHz模式下,性能达到90.2dB的信噪比（SNR）和86dB的动态范围（DR）。所设计的调制器的优值（FOM）同近几年来的低压调制器比较具有很大的竞争力。     

如何选择适合消费电子应用的实时时钟

实时时钟(Real Time Clock,RTC)是专用时钟集成电路,适合于一切需要低功耗及准确计时的应用,如手机、电视机和数码相机等消费电子设备,以及电表、供暖和通风等工业应用,医疗设备、办公自动化、汽车电子和测试测量领域也越来越多的采用了实时时钟.