Information processing cycle-?

Question

What exactly happens when we type a program in suppose C++. Explain me its processing through source code, object code, compiler/interpreter, ALU, MU & CU in detail.

Does the same sort of processing take place even when we do some small actions like opening or closing a file from our desktop?

Answer 1

You need to understand how a computer works, CPU, register and Memory and I/O movments and practice with some assembler programs in order to fully understand your question.

Computers only runs bits, we, humans, could represents colletion of bits as hexadecimal code or as assembler code, (but is only a representation). With assembler code is better for us to understand, but computer following work with bits.

Every assembler instruccion has a Identification Code, that would be used by CU (Control Unit) inside the CPU. When is time for that Instruction the Identification code is move from the memory to the Instruction Register (IR), and then passed to CU in order to decode that instruction.

But instructions are packed with data, so, depending on the instruction code, none, one or more bytes of data will follow to that code in memory and will be moved to MBR (Memory Buffer Register) in order move, later, to different Internal Register on the CPU.

When all the data are in the requires register the ALU operates and the result will keep in the Acumulator Register.

If you need some data from the 'outside', including a hard disk, you need to activate Input Output devices that will consume a lot of time and other computer resources like DMA (Direct Memory Access).

The process is simple, but haves so many details that is hard to undersat.

Please, get a copy of Stallings' book Conputer Architecture. Is a very dicactic book to understand the whole process

We used it at the University to teach the students