Q27,paper 3, J 12. Identify the addressing modes of below instructions and match them :

Options (a) ADI ------------- (1) Immediate addressing
(b) STA ---------------- (2) Direct addressing
(c) CMA -----------------------(3) Implied addressing
(d) SUB -----------------------(4) Register addressing
(A) a – 1, b – 2, c – 3, d – 4
(B) a – 2, b – 1, c – 4, d – 3
(C) a – 3, b – 2, c – 1, d – 4
(D) a – 4, b – 3, c – 2, d – 1
Answer (A)
Explanation. The addressing mode of certain instructions is implied by the instructions functions. Register addressing specify one of the address A-E,H or L. with these instructions Accumulator is assumed as the second operand. Ex CMP E ( compares the register E with accumulator) generally it deals with 8 bits when 16 bits are to be dealt like(PC HL) it exchanges Program counter with H and Lc. Immediate addressing assembles the data as part of instruction itself ex.(cpi c means the compare the contents of accumulator with c. Direct addressing include a 16 bit address as part of instruction.(ex jmp 1000H.) Register indirect instruction reference memory via a register pair(ex Mov M,C move the contents of C register into memory address stored in H and L register pair.