A control bus is a computer bus

Computer bus

In computer architecture, a bus is a subsystem that transfers data between components inside a computer, or between computers.Early computer buses were literally parallel electrical wires with multiple connections, but the term is now used for any physical arrangement that provides the same...

, used by CPU

Central processing unit

The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...

s for communicating with other devices within the computer. While the address bus carries the information on which device the CPU is communicating with and the data bus carries the actual data being processed, the control bus carries commands from the CPU and returns status signals from the devices, for example if the data is being read or written to the device the appropriate line (read or write) will be active (logic zero).

Lines

The number and type of lines in a control bus varies but there are basic lines common to all microprocessors, such as:

• Read (). A single line that when active (logic zero) indicates the device is being read by the CPU. As opposed to a write operation where data goes from the CPU to memory (or an i/o device).
• Perform a hard reboot.

External links

• Definition by Webopedia.
• Computer system organization at the University of California, Riverside
  University of California, Riverside
  The University of California, Riverside, commonly known as UCR or UC Riverside, is a public research university and one of the ten general campuses of the University of California system. UCR is consistently ranked as one of the most ethnically and economically diverse universities in the United...
  
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