Data bus

The data bus is a bus that carries the actual data between the processor and the main memory, so the processor can read or write data to the main memory or send and receive data from other components.

The width of the data bus (the number of bits it can carry at a time) determines how much data the processor can read or write to memory at a time - in each clock cycle. For example, if the data bus is 64 bits wide, then the processor can read or write 64 bits of data to memory in each clock cycle.

What does the data bus transfer?

• The data to be read from or written to memory
• The instructions that the processor needs to execute
• The results of calculations that the processor has done, so they can be stored
• The data that the processor needs to send to other components, like the graphics card, sound card, printers, etc.
• The data that the processor receives from other components, like user input from the keyboard, mouse, etc.