美国莫托洛拉公司生产的大规模集成电路MC6840是可编程定时器。使田MC6840可以生产不同频率、不同占空比的各种脉冲信号,可以定时发出单脉冲信号,可以进行频率测定和脉冲周期测定。MC6840通过程序控制设定它的多种用途,使用起来非常方便。它广泛地用于键盘,CRT等外部设备的波特率选择,可作为定时装置、时钟、频率计使用。在工业自动控制中可用作时间程序控制器,可做工业控制时标,也可以在测试仪或测试系统中做可编程序的定时单元。它与其它装置相比具有集成度高,成本低,精度高,便于调整维护等特点。使用MC6840一般是在微型机单板机小,或微型机系统中由CPU通过总线来控 The MC6840, manufactured by Motorola, USA, is a programmable timer. Field Tian MC6840 can produce different frequency, different duty cycle of a variety of pulse signals, you can regularly send a single pulse signal, you can determine the frequency and pulse duration measurement. MC6840 through the program control set its many uses, very easy to use. It is widely used in the baud rate selection of external devices such as keyboards and CRTs, and can be used as a timing device, clock, and frequency meter. In industrial automation can be used as a time program controller, industrial control can do time scale, you can also do in the tester or test system programmable timing unit. Compared with other devices, it has the characteristics of high integration, low cost, high precision, easy to adjust and maintain. MC6840 is generally used in the small single-board microcomputer, or microcomputer system by the CPU to control through the bus