It is a group of wires or lines that are used to transfer the addresses of Memory or I/O devices. It us unidirectional. In Intel 8085 microprocessor, Address bus was of 16 bits. This means that Microprocessor 8085 can transfer maximum 16 bit address which means it can address 65,536 different memory locations.
In this regard, what is the purpose of the address bus?
The address bus carries the address of the piece of memory or I/O device to be read from or written to. It is a unidirectional bus, which is to say that data travels only one way; from the CPU to memory. The number of lines on the bus determines the number of addressable memory elements.
What is the difference between the data bus and the address bus?
Address and data buses may have different widths, that is, they may carry different number of bits. Yes, memory bus usually means data bus (that carries the memory data). In isolation, the microprocessor, the memory and the input/output ports are interesting components, but they cannot do anything useful.
What is 20 bit address bus?
For example, an 8-bit-byte-addressable machine with a 20-bit address bus (e.g. Intel 8086) can address 220 (1,048,576) memory locations, or one MiB of memory, while a 32-bit bus (e.g. Intel 80386) addresses 232 (4,294,967,296) locations, or a 4 GiB address space.