Sphinx University
Microprocessors (1)
Faculty of Engineering
Sheet (1)
Department of Electronics and Communications
1. Do programs written for the 88/86 run on 80286-, 80386-, and 80486-based CPUs?
2. What do "BIU" and "EU" stand for, and what are their functions?
3. Which of the following registers cannot be split into high and low bytes?
(a) CS
( i) DI
(d) SS
(g) CX
(b) AX
(e) BX
(h) SI
(c) OS
(I) OX
4. Which of the following instructions cannot be coded in 8088/86 Assembly lan guage? Give the
reason why not, if any. To verifY your answer, code each in DEBUG. Assume that all numbers are
in hex.
(a)MOV AX,27
(e) MOV SI,9516
(i) MOV CH,AX
(b) MOVAL,97F
(c) MOV DS,9BF2
(f) MOV CS,3490
(g) MOV DS,BX
(j) MOV AX,23FB9 (k) MOV CS,BH
(d) MOV CX,397
(h) MOV BX,CS
(I) MOV AX,DL
5. If CS ~ 3499H and IP ~ 2500H, find:
(a) The logical address
(b) The physical address
(c) The lower and upper ranges of the code segment
6. Assume that the physical address for a location is 0046CH. Suggest a possible logical address.
7. should be assigned to CS if the IP must be ~ 1282?
Using DEBUG, assemble and unassemble the following program and provide the logical address,
physical address, and the content of each address location. The CS value is decided by DOS, but
use IP ~ 170H.
MOVAL,76H
MOVBH,8FH
ADDBH,AL
ADDBH,7BH
MOVBL,BH
ADDBL,AL
8. Repeat Problem 20 for the following program from page 29.
MOV AL,0
;c1ear AL
ADD AL,[0200]
;add the contents ofDS:200 to AL
ADD AL,[0201]
;add the contents ofDS:201 to AL
ADD AL,[0202]
;add the contents ofDS:202 to AL
ADD AL,[0203]
;add the contents ofDS:203 to AL
ADD AL,[0204]
;add the contents ofDS:204 to AL
9. Assume that SP ~ FF2EH, AX ~ 329lH, BX ~ F43CH, and CX ~ 09. Find the content of the
stack and stack pointer after the execution of each of the following instructions.
PUSH AX
PUSH BX
PUSH CX
10. In order for each register to get back their original values in Problem 29, show the sequence of
instructions that needs to be executed. Show the content of the SP at each point.
11. The following registers are used as offsets. Assuming that the default segment is used to get the
logical address, give the segment register associated with each offset.
(a)BP
(b)DI
(d) SI
(e) SP
(c)IP
(I) BX
12. Find the status of the CF, PF, AF, ZF, and SF for the following operations.
(a)MOV BL,9FH
ADD BL,6lH
(b) MOV AL,23H
ADD AL,97H
(c) MOV DX,10FFH
ADD DX,1