Question

Input output devices used in embedded system

Answer 1

NPUT AND OUTPUT DEVICES
Input and output devices usually have some analog or non-electronic component— for instance, a disk drive has a rotating disk and analog read/write electronics. But the digital logic in the device that is most closely connected to the CPU very strongly resembles the logic you would expect in any computer system.
the structure of a typical I/O device and its relationship to the CPU. The interface between the CPU and the device’s internals (e.g., the rotating disk and read/write electronics in a disk drive) is a set of registers. The CPU talks to the device by reading and writing the registers.

Devices typically have several registers, 

■ Data registers hold values that are treated as data by the device, such as the data read or written by a disk.

 

■ Status registersprovide information about the device’s operation, such aswhether the current transaction has completed.

 

Some registers may be read-only, such as a status register that indicates when the device is done, while others may be readable or writable. Application describes a classic I/O device.