Question

Multiplexing of address and data lines is used in
1. Intel 8086
2. Z80
3. 6502
4. MC68000

Answer 1

Correct Answer - Option 1 : Intel 8086

Bus Types:

• Bus lines can be separated into two generic types: dedicated and multiplexed.
• A dedicated bus line is permanently assigned either to one function or to a physical subset of computer components.
• In a multiplexed bus, address and data information may be transmitted over the same set of lines using an Address Valid control line. This method of using the same lines for multiple purposes is known as time multiplexing.
• The advantage of time multiplexing is the use of fewer lines, which saves space and, usually, cost.
• The disadvantage is that more complex circuitry is needed within each module. Also, there is a potential reduction in performance because certain events that share the same lines cannot take place in parallel.

Data Bus:

• Data bus is responsible for transferring data to the memory and fetching data from the memory.
• The program that is to be run and associated data both are stored as data only in memory.
• Word length of a processor is the maximum number of bits it can accept as input, process, or deliver as output. The word length of a processor is equivalent to the data bus. Therefore, data bus decides the number of bits transferred at one time.

Multiplexing of address and data lines is used in 8085 and 8086.