Memory Address Space Calculator
Calculate the total addressable memory from the number of address lines and data bus width.
Total Addressable Memory
65,536 bytes
Total Addressable Memory vs Address Bus Width (bits)
Formule
## Memory Address Space The address bus width determines how many unique memory locations a processor can access. ### Formula **Locations = 2^Address_Bits** **Total Memory = Locations x (Data_Bus_Width / 8) bytes** ### Common Examples - 8-bit address: 256 bytes - 16-bit address: 64 KB - 20-bit address: 1 MB (original PC) - 32-bit address: 4 GB - 64-bit address: 16 EB (theoretical)
Exemple Résolu
16-bit address bus with 8-bit data bus.
- 01Locations: 2^16 = 65,536
- 02Bytes per location: 8/8 = 1
- 03Total: 65,536 x 1 = 65,536 bytes
- 04In KB: 65,536 / 1024 = 64 KB
Questions Fréquentes
Why can 32-bit systems only address 4 GB?
2^32 = 4,294,967,296 bytes = 4 GB. Physical Address Extension (PAE) can extend this on some architectures.
Does data bus width affect address space?
Not the number of locations, but it affects total bytes. A 16-bit data bus accesses 2 bytes per location.
What is memory-mapped I/O?
Hardware registers are placed in the address space, reducing available RAM but simplifying peripheral access.
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