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How many memory locations can be accessed if we are having an 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.
How many memory locations can a processor address?
What will be the maximum capacity of a memory which uses an address bus of size 8-bit?
13.6 Memory addressing size
| Address bus size | Addressable memory (bytes) |
|---|---|
| 7 | 128 |
| 8 | 256 |
| 9 | 512 |
| 10 | 1K* |
How do you calculate address bus width?
So to work out the amount of addressable memory, we must multiply the number of addresses by their size.
- Total Addressable Memory = (2^address bus width) * Data bus width.
- IE a machine with a 16 bit Data Bus and 32 bit address bus would have.
- (2^32)*16 bits of accessible storage.
- or 8GB – Do the math yourself to prove it.
How many addresses can a 12-bit address bus?
Hence, a microprocessor with 12-bit memory addresses can directly access 4096 words (4 Kw) of word-addressable memory.
What will be the size of its address bus?
The size of the address bus determines how much memory the CPU can address directly. For example, a 20-bit address bus can access up to one megabyte (1MB); 24 bits reaches 16MB, and 32 bits can handle four gigabytes (GB).
How do I find the address size?
Step 1: calculate the length of the address in bits (n bits) Step 2: calculate the number of memory locations 2^n(bits) Step 3: take the number of memory locations and multiply it by the Byte size of the memory cells.
What is bus width?
Bus width refers to the number of bits that can be sent to the CPU simultaneously, and bus speed refers to the number of times a group of bits can be sent each second. A bus cycle occurs every time data travels from memory to the CPU. Latency refers to the number of clock cycles needed to read a bit of information.