| 释义 |
I/O hardware control /output device must initiate and control the data transfer directly into or from microcomputer memory.Often the software support is limited to the initiation, termination, and recovery aspects of the transfer.These aspects are often performed automatically without microprocessor intervention.The hardwarecontrol approach is also known as directmemory access or data break.It can be used to transfer blocks of characters directly between a peripheral device——such as tape, cassette, or floppy disk——and main microprocessor memory.；许多新型的中央处理机采用的一种数据传输的方法。这种方法需要大量的附加硬件, 这是由于输入输出设备必须启动和控制数据传输直接进出微型计算机内存。软件支持常常限于传输的起始、结束和恢复等方面,这些方面常常无需微处理机干预即被自动完成了。硬件控制方法也称为直接存储器存取或数据中断,它可以在微处理机内存和外部设备如磁带、盒式带或软盘之间直接传输字符块。 |