74922芯片是专用编码键盘接口芯片 ,当按下某一按键时 ,该芯片能自动给出相应的编码信息 ,并可自动消除抖动 ,从而可使设计者免除一部分软件编程。-74922 chip is dedicated coding keyboard interface chip, when a button is pressed, the chip can automatically given the appropriate coding information, and automatically elimin