STC:- It is logical instruction or logical instruction used to set the carry flag in a computer.
- The carry flag is a single bit in a system status register/flag register used to indicate when an arithmetic carry or borrow has been generated out of the most significant arithmetic logic unit (ALU) bit position.
- The carry flag enables numbers larger than a single ALU width to be added/subtracted by carrying (adding) a binary digit from a partial addition/subtraction to the least significant bit position of a more significant word.
1 Data Transfer
The data transfer instructions move data between registers or between memory and registers.
MOV , MVI,LDA,STA,LHLD,SHLD etc.
The Instructions under this group perform logical operation such as AND, OR, compare, rotate etc. Examples are: ANA, XRA, ORA, CMP, RAL,STC etc.
3 Program control
instructions change or modify the flow of a program. The most basic kind of program control is the unconditional branch or unconditional jump. Branch is usually an indication of a short change relative to the current program counter. Jump is usually an indication of a change in program counter that is not directly related to the current program counter (such as a jump to an absolute memory location or a jump using a dynamic or static table), and is often free of distance limits from the current program counter.