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Widening the data bus
The width of the data bus determines the number of bits to be transferred in each memory access.
Using a wider data bus
- Allows simultaneous transfer of both instructions and its operands,
- Reduces the number of memory accesses, and
- Increases computation speed, but
- Increases system integration cost.
Another way to increase the memory access speed is to get more information with each memory access. This can be achieved by using a wider data bus. Several instructions or many bytes of data can be fetched simultaneously using a wide data bus. A wide data bus is especially suitable for high-end microprocessors where scalar structure is used. Wider data buses also support long instructions with multiple operands.
Wide data buses usually are not used for price-sensitive applications since wide data buses increases the number of CPU pins and hence increase the integration cost.