pointers seen on assembly or registries

Question

How does a pointer look like in assembly, I know a instruction like 'mov' for lets say a pic, is converted to a sequence of bits, these bits activate the circuits to do the job, but a pointer, how is it managed to assembly and then manage to control circuits?. a simngle pointer is transformed in several assembly instructions, how do they look like?

Answer 1

Pointer is nothing but a unsigned integer indicating position in a memory (virtual address space to be precise).

The instruction

mov eax,[ebp ]

Moves value stored in a memory location whose address is stored in ebp into eax. Here ebp is a pointer.

Coming back to your question. Code is also data stored somewhere in memory and address of that memory is pointer. So using [] for dereferencing the pointer we can get that instruction(as done in above statement) and then cpu can interpret the code and execute.

Actually on 32bit x36 machines register eip stores a pointer which points to the memory which got current instruction which is getting executed.

Answer 2

Pointers are memory offsets. They look like integers with a width appropriate for the addressable size of the memory segment.

Answer 3

The main feature of assembly is that a pointer can be present as label so that assemblers compiler can translate it to instructions op-code.

Actually any pointer is composed from one or more unsigned integers. At 8 bit PIC16 MCPUs you must first set appropriate memory bank, after that you can write in to memory, the reason is that address op-code size is only 7-bit in case that you are using direct memory addressing. You can also use indirect memory addressing in that case you must use FSR register that is composed from two 8-bit registers FSRL and FSRH. After setting pointer in FSR register you can read the result in INDF register as byte of that address.