32 bit address bus can access more than 4 gigabytes (232) of memory.
Sandeep Kr. Singh (MCA)
a 20 bit address bus has 2 power of 2o data lines which
provies us to utilisr the memory up 20 2 mb
(2^n)-1 (Since Addressing starts at zero)
0 - 1023
Addresses into bus width
232 = 4,294,967,296, or 4 G
232
4GB
1MB
An 80286 has a 24 bit address bus. As such, it can address 224, or 16,777,216, or 16 MB of memory.
A memory with a 16 bit address bus can address 216 or 65536 distinct items. If each item is 32 bits in size, then the item is 4 bytes. The size of this memory is then 262144 bytes. (256Kb)
A 14 bit address bus can select 16384 locations.
Even though the 8085 is an 8 bit microprocessor, it can address 64K memory, because it has a 16 bit address bus.
A 10 bit address bus can address 210, or 1024 different locations.
A 16-bit uP operates on instructions and data in 16-bit quantities. Therefore the databus is 16-bits. A 16-bit uP may also operate on larger quantities of data, however multiple CPU registers must be concatenated in order to maintain the data element in the uP register space. The data is always delivered to the processor 16 bits at a time. The amount of memory which it can address is a separate issue---the address bus size is totally distinct from the data bus size. The data bus determines how much memory may be delivered to the uP per cycle. The address bus size determines how much physical memory may actually be accessed by the uP. Therefore it is variable depending on how much memory is available. Typical systems today have 32-bit address busses which limit addressable memory to 4Gigabytes. (2^32) = 4G.
The memory capacity of the 8085 microprocessor is 64 kb because the address bus is 16 bits, and you can address 216, or 64kb, with a 16 bit address bus.
The data bus in the 8086 is 16 bits in size, while the address bus is 20 (16bits would only address 64KB of memory, an extra 4 bits allows to address the total of 1MB, this is done trough segmentation of the memory). To form a multiplexed of data bus and address bus, four bits of 8086 address bus are grounded.
2^14 memory locations. In general for n-bit address bus, its 2^n
1TB is 240 bytes. It follows that a 40 bit address bus can address 1TB. Since 1TB is 1TB regardless of the system's word size, a 40 bit address bus can address 1TB on a computer with an 8 bit, a 16 bit, a 32 bit, or any other word size.
A 16 bit address bus can select 65536 locations.
The 8086/8088 microprocessor has a 20 bit address bus, so the number of memory locations it can address is 220 or 1,048,576.