Bus Interface Unit

Bus Interface Unit
A unit to interconnect the internal buses with the external buses for control, address and data bits.

Memory Data Register

Memory Data Register
A register that holds the data fro or from a memory unit.

Memory Address Register

Memory Address Register
A register that holds the address for a memory unit for placing it on the bus using bus interface unit. 

Internal Bus

Internal Bus
A set of paths that carry in parallel the signals between various internal structure units of a processor. Its size is 64 bit in a 64-bit processor.

Output Buffer

Output Buffer
A register buffer from where an output device receives the byte after a processor -write operation.

Input Buffer

Input Buffer
A buffer where an input device puts a byte and the processor reads it later.

Serial Port

Serial Port
A port for read and write operations with one bit at an instance and where each bit of the message is separated by constant timer intervals.