What is A-instruction and C-intruction.

[ajilraju]

Hello World,

          I have a doubt about what is A-intruction and C-intruction, Actually i figure out what it's mean in our nand2tetris computer, but my question is that, This is like a standard, compare to old Intel 8080-86 processors. Anyone know comparison b/w the intel old processor and our nand2tetris (A/C instruction)?

* We have (nand2tetris)
1) A-instruction
2) C-Instruction

* Intel have

1) ???
2) ???

anyone please clarify the ???

[WBahn]

There really is no meaningful direct comparison.

Each processor has an Instruction Set and the sets for two completely different families of processors may or may not have any significant overlap.

Many processors support some kind of a "load immediate" instruction whose sole (or primary) purpose is to load a constant into a register. That would correspond to an A-type instruction.

The C-type instructions don't have a close analog in most instruction sets because few real architectures are set up to do three things in a single instruction -- compute a value, store the value in multiple locations, and perform a conditional branch.