Hi guyz, i need help on the following questions



1. Give an example instruction of every addressing mode of 8051 and explain in detail
how the addressing mode is used in the instruction. If your example instruction has two
operands, tell which one of the operands is addressed by the mode you have mentioned.

2. Write different short programs that
a) clear the two least significant bits of R2 without changing the other bits,
b) set the three most significant bits of R3 without changing the other bits,
c) subtract the contents of the accumulator from register R4. SUBB A,R4

3. What are the contents of the accumulator after the execution of the following instructions?
It is assumed that the contents are 55H before each instruction.
a) INC A
b) ADD A,#10B
c) ANL A,#33H
d) ORL A,#33H
e) RR A
f) CPL A

4. Intel 8051 external memory locations 3001...304FH contain 8-bit binary numbers. Write a
program that calculates how many of the numbers are equal to 0 and writes the result in
memory location 3000H.

5. How have the contents of Intel 8051 memory changed when the following program has
been executed? Notice that also registers and special function registers are located in the
memory. Register bank 0 is in use.

MOV R0,#2H
MOV R1,0H
MOV DPTR,#8800H
MOV A,#0AAH
MOVX @DPTR,A
INC DPTR
CPL A
SETB C
RLC A
L1: INC DPTR
MOVX @DPTR,A
DEC R0
MOV A,R0
CJNE A,#0H,L1
ADD A,R1
L2: SJMP L2

 

Could it be that you do not have the instruction set? - http://www.win.tue.nl/~aeb/comp/8051/set8051.html

Some close reading and you can find all the answers.

 

I have seen the instruction set, but the problem is i am not so familiar with microprocessor , so i just need help for the answers from anyone who will be a ble to do it. I have tried but am still stuck in all of those question. For question no1 its oki, i got it done, but the rest, am stuck, i dont know where to start