LOOPING AND JUMPING INSTRUCTIONS: DJNZ

Instruction: An instruction is an order or command given  to processor by a computer program,  set of instruction is known as program.

The DJNZ instruction decrements the byte indicated by the first operand and, if the resulting value is not zero, branches to the address specified in the second operand.

The INC instruction increments the specified operand by 1

The JZ instruction transfers control to the specified address if the value in the accumulator is 0. Otherwise, the next instruction is executed. Neither the accumulator nor any flags are modified by this instruction.



REFERENCE:

Registers

The CPU uses registers to store information temporarily,   The information could be two values to be processed or the address of the value needed to be fetched from the memory.

Registers inside CPU  can be 8-bit,16-bit,32-bit or event 64-bit registers.