电话系统智能去电控制器的设计(论文+电子通信类英文文献翻译)
The application of microcontroller
in closed caption systemAbstract
This paper describes our newly designed microcontrollers for Closed Caption system application. These microcontrollers integrate the Closed Caption decoding function and other functions required for TV set control.
1. Introduction
Microcontrollers that utilize the Closed Caption function have been developed. The Closed Caption decoding function must be provided for all TV sets sold in the U.S.fr on July 1993.
These basic system development guidelines were as follows:
(1) The system must provide stabilized reception.
(2) The system should offer low-cost operation.
The key word for this development was full-function. In regulations established on April 12,1991, the FCC specified the text mode as being optional, thus reflecting that committee on low-cost systems. With our goal of supplying Closed Caption hardware as a new information medium, we decided to develop a system satisfying the specifications for all options. Last year we introduced the add-on type of Closed Caption Decoder LSI kit designed for easy installation into existing TV sets. The Closed Caption decoding function is implemented efficiently by microcontrollers described in this paper. The high-performance
On-Screen Display function for Closed Caption application can be used for easy TV set operation.
This new microcontroller is a low cost, high accuracy instrumentation that requires only one external resistor to set gains of 1 to 10,000. Furthermore, This new microcontroller features 32-lead SOIC and DIP packaging that is smaller than discrete designs and www.751com.cn ccuracy of 40 ppm maximum nonlinearity, low offset voltage of 50 µV max, and offset drift of 0.6 µV/°C max, is ideal for use in precision data acquisition systems’ transducer interfaces. Furthermore, the low noise, low input bias current, and low power of This new microcontroller make it well suited for medical applications, such as ECG and noninvasive blood pressure monitors.
The low input bias current of 1.0 nA max is made possible with the use of processing in the input stage. This new microcontroller works well as a preamplifier due to its low input voltage noise of 9 nV/Hz at 1 kHz, 0.28 µV p-p in the 0.1 Hz to 10 Hz band, and 0.1 pA/Hz input current noise. Also, This new microcontroller is well suited for multiplexed applications with its settling time of 15 µs to 0.01%, and its cost is low enough to enable designs
with one DUT per channel.
2. System Overview
Our new microcontrollers provide TV systems with the Closed Caption function when used with the Front End LSI. Since the Front End LSI is designed with bipolar technology, it provides very stable operation even under weak or abnormal signal conditions. The microcontrollers employ an 8-bit CPU core and integrate the Closed Caption decoding function and all functions required for TV set control. This series of microcontrollers consist of an EP-ROM version, OTPROM version, and mask-ROM versions of 8K, 12K, 16K, 20K, 24K, 28K and 32K-byte ROM capacity. Except for ROM capacity, all other functions are exactly the same for simple installation into different types of TV sets. A microcontroller and the Front End LSI can replace the existing tuner microcontroller providing the Closed Caption decoding function. Therefore, a stable decoding function can be provided without a large expenditure for parts.
2.1 Front End
This LSI receives the composite video signal from the video signal processor and extracts the Caption Data from the signal. This LSI contains a bipolar device with a synchronizing separator circuit. By generating the Horizontal synchronizing signal and Vertical synchronizing signal by itself, this device extracts the caption signal from line 21. This LSI has two AFC blocks. AFC1 is the standard AFC block to stabilize the VCO (Voltage Controlled Oscillator) to 32MH. The signal from the video and another signal from the Horizontal C/D divided VCO output are sent to AFC1. AFC2 is the additional AFC block to synchronize the phase of VCO output for the caption signal. This design enables the clock to be regenerated with the frequency and phase synchronized. This LSI detects line 21 and only outputs the sliced signal， VCO output as clocks during the data period. In other words, clocks, data and the transmission signal (TRANS) are output during line 21 of each field. In addition, this LSI discriminates between odd and 1064
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