Instruction Comparisons

Instruction Comparisons

Example 2.6.1 Compare instructions SUB A and MVI A, 00H.

Solution :

Example 2.6.2 Compare instructions SUB B and CMP B.     

May-14, Marks 2         

Solution :

Example 2.6.3 Compare instructions LXI H, 2000H and LHLD 2000H.

Solution :

Example 2.6.4 Compare instruction JMP 2000 H and PCHL

Solution :

Example 2.6.5 Compare instructions HLT and NOP.

Solution :

Example 2.6.6 List out differences and similarities between CALL – RET and PUSH – POP instructions.

Solution : Differences :

Similarities :

1. They use stack memory.

2. CALL and PUSH instructions decrement stack pointer by 2.

3. RET and POP instructions increment stack pointer by 2.

4. Instructions do not affect flags except POP PSW instruction.

Review Questions

1. Compare the similarities and differences of CALL and RET instructions with PUSH and POP instructions

AU : Dec.-11, Marks 8

2. Explain the operational difference between the following pairs of instructions.

i) SPHL and SHLD addr

ii) CALL addr and JMP addr

iii) LHLD and SHLD addr

iv) XRA A and MVI A, 00H

v) INR A and ADI 01 H

vi) DAD RP and DAA.