The 'Registers on Bus' Computer Architecture

The overall design of a computer is called its computer architecture. The architecture of the computer in the book 'How Computers Work: Processor and Main Memory (including the second edition) and described so far is called the 'Von Neumann' architecture. The 'registers on bus' architecture is so like the Von Neumann architecture that it might better be called the 'modified Von Neumann architecture' or the 'parallel Von Neumann architecture.'

The Von Neumann architecture consists of a memory, processor, clock, data bus, address bus, and control bus. The memory consists of latches, an address decoder, control logic (control circuitry), an address bus, and a data bus. The processor consists of registers (latches), an address bus, a data bus, a logic unit (usually called an ALU ('Arithmetic Logic Unit' if it can do arithmetic) and control logic (circuity). The clock is a circuit that repeatedly generates a pattern of 1's and 0's on various lines (wires). The address bus is a group of wires that connect to each latch in memory and select the latch to be accessed. The data bus is a group of wires that connect to each of the memory's latch's bits (loops in the book) and to registers in the processor. The control bus is a group of wires that go from the clock to the processor and memory to signal each as to what to do at each time.

A diagram of the Von Neumann architecture is shown below.

Von Neumann architecture

The computer in the book is an example of the Von Neumann architecture. A diagram of it is shown below.

Example of Von Neumann architecture

Notice the data bus that connects to the latches of memory, the input and output latches, and the registers. Also notice the address bus connected to the memory and input and output latches. Such a data bus and address bus almost define the Von Neumann architecture.


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