How does the CPU generate a memory address?

[Beno]

Hi,

When a program is executing, I know that programs have instructions but how is the CPU addressing memory or how is the program addressing memory??.......I mean what is giving the CPU the proper addresses to access memory ........is the actual program itself??? and if it is then how does the program know not to access a certain block of memory that it is not supposed to....etc....etc

This is just an interesting point that has been on my mind for ages! :-)
so if any of you comp.sc guru's can answer it then that would help solve my quering mind!!

Thanks

Beno


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Have a nice day

[Paleo Pete]

As best I understand it, numerical memory addresses are mapped during boot, (memory mapping) giving the physical memory numerical equivalents the CPU and OS can relate to, since the computer sees everything as numbers.

The application sends a notice to the CPU that it needs a certain amount of memory to operate, and the CPU sends a signal to himem.sys, which allocates that amount of memory to the available numerical addresses. Himem.sys is the memory manager that does the "grunt work".

This is a VERY simplified description, it's actually much more detailed than that, but that should give you the basics.

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