Computer System Organization• Computer-system operation
– One or more CPUs, device controllers connect through
common bus providing access to shared memory
– Concurrent execution of CPUs and devices competing
for memory cycles
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.