Input/output operations
The goal of the I/O portion of a processor architecture is to efficiently transfer data between external peripheral devices and system memory. Input operations transfer data from the external world into memory and output operations send data from memory to an outside destination.
The format of the data on the external side of the I/O interface varies widely. Here are some examples of the external representations of computer I/O data:
- Signals on a video cable connected to a monitor
- Voltage fluctuations on the wires in an Ethernet cable
- Magnetic patterns on the surface of a disk
- Sound waves produced by computer speakers
Regardless of the form the data takes when it is outside the computer, the connection of any I/O device with the processor must comply with the processor's I/O architecture, and the I/O device must be compatible with any other I/O devices that happen to be present in the computer system.
The processor uses...
