NEC 128 manual Technical Description, System Control

Page 23

3-1

Technical Description

VisuaLink 128 and VisuaLink 384 employ the latest Codec (coder/ decoder) technology for digital video/audio applications. VisuaLink employs echo cancelling and control system logic to enhance the signal clarity and ease of use.

The diagram illustrates the main functional elements of VisuaLink.

VisuaLink Functional Block Diagram

Video Sources

Video

&

 

 

Interface

Monitors

H.320

 

Line

 

BRI Line

 

 

Network

Codec

 

Interface

 

 

 

Interface

Audio Sources

Audio

 

Echo

&

 

 

 

 

 

Interface

 

Canceller

Speaker

 

System Control

Infrared Remote Control, Serial Port,

Analog Telephone or VoicePoint+

The following sections provide a technical overview for each of these elements.

VisuaLink 128/384 General Description

Image 23
Contents VisuaLink 128/384 NDA-24229, IssueLiability Disclaimer Contents Specifications Overview IntroductionFeatures Videoconferencing Compliance Echo CancellerPhone-Like Dialing Camera ControlPBX Connectivity Field UpgradableApplications Isdn BRI VisuaLink Documentation Introduction VisuaLink 128/384 General Description Roll-About Desktop PC Gateway Application ConfigurationsEasily moved, use in active locations Roll-AboutVideo Monitor Roll-About ComponentsVideo Cabinet VisuaLink 128/384Options Motion Video CameraMicrophone Cable KitAlso available with control software Desktop PCCCD Desktop Camera Desktop PC ComponentsVideo Capture Board NT1 Graphics Camera D30 Camera AT841/INT Microphone VisuaLink Director SoftwareLaptop PC option Personal Computer RequirementsVisuaLink & ViewPoint VBX Gateway GatewayVisuaLink Direct Connect Gateway System Control Technical DescriptionVideo Echo CancellerVideo & Audio Interfaces CodecLine Interface System ControlVideo Frame Rate Picture ResolutionMore on H.320 Videoconferencing For Example Video ProcessingAudio Data Transmission RateTechnical Description VisuaLink 128/384 General Description Installation Requirements Installation & MaintenanceMaintenance Requirements General Specifications SpecificationsPage General Parameters Parameter VisuaLinkUnit Size Line Interface External Interface ParametersSerial Incoming Call Answer Modes Operating Modes & FeaturesVisuaLink Unit Control Call Dialing Originating ModesAudio Control Modes Line Interface ControlLine Connect Modes Video Display/Output ModesMulti-Point Conference Control MaintenanceSerial Port Modes VisuaLink 128/384 General Description

128 specifications

The NEC 128 is a remarkable microprocessor that represents a significant leap in technological innovation during its time. Introduced in the early 1980s, this processor was designed to meet the demands of increasingly sophisticated computing tasks, primarily aimed at the burgeoning field of personal computing and embedded systems.

One of the standout features of the NEC 128 is its 16-bit architecture, which was quite advanced for its era. This architecture allows for a greater data throughput, enabling the handling of larger data sets and providing improved performance over its predecessors. The NEC 128 operates on a clock speed that typically ranges from 4 to 8 MHz, making it capable of executing instructions efficiently and swiftly, which was crucial for running more complex applications.

The processor is built using CMOS technology, which offers significant advantages in terms of power consumption compared to earlier bipolar technology. This characteristic made the NEC 128 not only suitable for desktop computing but also an appealing choice for battery-operated devices, enhancing its versatility. The use of CMOS allowed for a reduced heat output, contributing to the reliability and longevity of devices powered by this microprocessor.

Another noteworthy aspect of the NEC 128 is its support for a variety of addressing modes. This flexibility enables programmers to write more efficient and compact code, optimizing the use of memory resources. By supporting both immediate and indirect addressing, the NEC 128 allows for more dynamic programming, which is essential for developing applications that require real-time processing.

The processor's architecture also includes a robust instruction set that facilitates arithmetic operations, logical operations, and control flow management. This comprehensive instruction set is instrumental for developers, as it provides the necessary tools for creating a wide range of applications, from simple utilities to more complex software systems.

In summary, the NEC 128 microprocessor is characterized by its 16-bit architecture, efficient CMOS technology, and a versatile instruction set, making it a compelling choice for its era. Its combination of performance, power efficiency, and flexibility positioned it as a formidable player in the personal computing market and laid the groundwork for future advancements in microprocessor technology. With its various applications and features, the NEC 128 remains a noteworthy chapter in the history of computing.