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) 第3页
is determined by the horizontal position of the character to be displayed. The 32 characters have to be displayed in one line
and each character consists of an eight-dot horizontal attribute specification code according to the mode used. Italics, flash, underline, and character color are specified in the caption and text modes. Character background color and character color are specified in 16-line OSD mode and 8-line OSD mode.
5. Other Features in OSD Mode
The following OSD mode features are also provided:
- 8 character colors
- 8 character background/fringe colors
- 8 full screen background colors
- Normal-size, double-size, and quadruple-size character
- Smooth scroll function
The high performance OSD function is ideal for menu-driven systems. Figure 8 shows an sample of a menu-driven system that uses a display format.
6. Software Support System
July 1,1993 is the deadline for all TV manufacturers to implement the closed caption system. To complete development in this limited time, the software support system is very important. To make programming more efficient, we developed a development tool with real time debugging capability and source line debugging capability. The real time capability is enabled by special system configuration. The development tool is directly built into the personal computer bus. With this method, the
internal registers of the microcontroller can be displayed onscreen in real time. With source line debugging function, every debugging operations, such as break, trace, or step function can be executed on source line. The source line debugging function is also supported on the C language. Paperless debugging can be done with this function. We also www.751com.cn of the system. It provides a direct means of injecting a precise offset to the output, with an allowable range of 2 V within the supply voltages. Parasitic resistance should be kept to a minimum for optimum CMR.
7.2 Input protection
This new microcontroller features 400 Ω of series resistance at its inputs and will safely withstand input overloads of up to ±15 V or ±60 mA for several hours. This is true for all gains and power on and off, which is particularly important since the signal source and amplifier may be powered separately. For longer time periods, the current should not exceed 6 mA. For input overloads beyond the supplies, clamping the inputs to the supplies will reduce the required resistance, yielding lower noise
7.3 Common-mode rejection
This new microcontroller, offer high CMR, which is a measure of the change in output voltage when both inputs are changed by equal amounts. These specifications are usually given for a full-range input voltage change and a specified source imbalance. For optimal CMR, the reference terminal should be tied to a low impedance point, and differences in capacitance and resistance should be kept to a minimum between the two inputs. In many applications, shielded cables are used to minimize noise; for best CMR over frequency, the shield should be properly driven.
7.4 Ground returns for input bias currents
Input bias currents are those currents necessary to bias the input transistors of these microcontrollers. There must be a direct return path for these currents. Therefore, when amplifying  input sources, such as transformers or ac-coupled sources, there must be a dc path from each input to ground. Refer to A Designer’s Guide to these microcontrollers for more information regarding applications.
7.5 Simplified Schematic of this microcontroller
This new microcontroller is a new microcontroller based on a modification of the classic approach. Absolute value trimming allows the user to program gain accurately (to 0.15% at G = 100) with only one resistor. Monolithic construction and laser wafer trimming allow the tight matching and tracking of circuit components, thus ensuring the high level of performance inherent in this circuit. The input transistors Q1 and Q2 provide a single differential-pair bipolar input for high precision, yet offer 10

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