A device controller has a local buffer storage and a set of registers

A device controller has a ….

The ….. is responsible for moving the data between the peripheral devices that it controls and its local buffer storage

The operating system provides …. that understands the ….. and provides a uniform interface to the device

….loads the registers within the …

… determines action to take based on registers

Device controller determines action to take based on …

…. transfers data between device and its local buffer

… generates an interrupt to inform the ….

… returns control to the operating system

Device Driver possibly returning the data if the operation was a …

For other operations, the device driver returns

This is fine for moving small amounts of data but can produce high overhead on the CPU when used for bulk data movement

With Direct Memory Access Device controller transfers an entire block of data between

Device controller generates only one interrupt per …., to inform the device driver, rather than one interrupt per

With Direct Memory Access While the device controller is transferring a whole data block, the CPU is available to accomplish other work

…….. processor supports a complete instruction set

……. processor supports a limited instruction set

….. can execute user processes

…. cannot execute user processes

…… processors include device-specific processors, such as disk, keyboard, and graphics controllers