How a Modern Computer System Works

How a Modern Computer System Works

Computer-System Operation

• I/O devices and the CPU can execute concurrently
• Each device controller is in charge of a particular device type
• Each device controller has a local buffer
• CPU moves data from/to main memory to/from local buffers
• I/O is from the device to local buffer of controller
• Device controller informs CPU that it has finished its operation by causing an interrupt

Direct Memory Access Structure

• Used for high-speed I/O devices able to transmit information at close to memory speeds
• Device controller transfers blocks of data from buffer storage directly to main memory without CPU intervention
• Only one interrupt is generated per block, rather than the one interrupt per byte

참고  : Operating System Concepts by WILEY