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NASM Forum => Other Discussion => Topic started by: mostafaxx on January 28, 2013, 06:58:02 PM

Title: memory addressing system
Post by: mostafaxx on January 28, 2013, 06:58:02 PM

hello every one,

i have a question a bout how a computer system address memory,

i know that a 32bit processor can't address memory more than 4294967296 bytes that is 4 GB
because it's address bus is only 32bit long and its registers are 32bit long,

now how could a computer address plus to the 4gigs of memory a 300GB hard disk and 16GB flash memory???

Title: Re: memory addressing system
Post by: Frank Kotler on January 28, 2013, 08:44:03 PM

Two registers...

Best,
Frank

Title: Re: memory addressing system
Post by: Keith Kanios on January 29, 2013, 12:03:27 AM

Quote from: mostafaxx on January 28, 2013, 06:58:02 PM

now how could a computer address plus to the 4gigs of memory a 300GB hard disk and 16GB flash memory???

If I understand correctly, you are asking how a computer can address 4GB of RAM, a 300GB hard disk and 16GB of flash memory all on the same 32-bit address bus.

The short answer is that devices such as hard disks and flash memory are not mapped entirely into the address bus, but accessed in blocks/sectors.

Read up on terms like CHS/LBA/PATA/SATA/ACHI for more information.