Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
The address bus of any microprocessor is always_____.
Unidirectional
Bi-directional
Either of one
None
Unidirectional
The address bus in a microprocessor is always unidirectional because the processor is the sole entity responsible for generating and placing the physical address on the bus to identify a memory location or I/O port. Information flows exclusively from the CPU to the memory or peripheral devices, which then respond to the requested address.
The address bus in a microprocessor is always unidirectional because the processor is the sole entity responsible for generating and placing the physical address on the bus to identify a memory location or I/O port. Information flows exclusively from the CPU to the memory or peripheral devices, which then respond to the requested address.
N=2┬░n тАФ where N is the total addressable memory locations and n is the number of address bus lines.
The CPU uses the address bus to specify the target location in memory (M) or the I/O address (I/O) for a read or write operation. Since the microprocessor is the 'master' that initiates communication, it does not need to receive address information from memory or peripherals, making a bidirectional path unnecessary and redundant.
Address bus width determines the maximum memory capacity of the processor.
Unidirectional flow ensures clear communication control by the CPU.
Data buses are bidirectional, whereas address buses and control buses (mostly) are unidirectional.
Simpler control logic
Reduced hardware complexity by limiting signal direction
Prevents bus contention for address signals
Limits physical communication to one-way master-to-slave operation
Cannot be used for peer-to-peer memory access without arbitration
Memory interface
I/O device selection
System control signals
In an 8085 microprocessor, the address bus is 16 bits wide, allowing addressing up to 2┬░16=64 KB.
Option B is incorrect because bidirectional buses (like data buses) allow signals to flow in both directions between CPU and memory/peripherals.
A is correct тАФ The address bus is unidirectional because addresses are sent only from the CPU to external memory or peripherals.
Always remember: Address is sent by the master (CPU) only, while data is transferred both ways; therefore, Address Bus = Unidirectional, Data Bus = Bidirectional.