论文部分内容阅读
遥控彩电的CPU的键控输入方式有两种:即矩阵扫描式和电阻分压式。矩阵式键控多见于早期生产的电视机,其缺点是空输出和输入脚占据CPU较多引脚,如一个4×4键盘就占据CPU的八只引脚,而且键控板到CPU的引线又多等弊病;现在生产的电视机大多采用分压式键控,其CPU只有一二只键控输入脚,通过外接键控板上不同的分压电阻,就有不同的键控电平送到CPU,再经内部A/D转换,变成CPU能识别的功能(二进制代码),实现控制功能。现举例如下:
There are two types of key input methods for remote color TV CPU: matrix scanning and resistor divider. Matrix keying more common in early production of television sets, the disadvantage is that empty output and input pin occupy the CPU more pins, such as a 4 × 4 keyboard occupy the CPU’s eight pins, and keying board to the CPU lead And so many ills; now most of the TV production using partial pressure keying, the CPU only one or two keying input pin, by an external keying board different voltage divider resistors, there are different keying level to send To the CPU, and then by the internal A / D conversion, into the CPU can identify the function (binary code), to achieve control functions. Here is an example: