Question

Assume that the registers have the following values (all in hex) and that CS= 1000, DS = 2000,
SS=3000, SI=4000, DI = 5000, BX=6080, BP= 7000, AX=25FF, CX=8791, and DX=1299. Calculate
the physical address of the memory where the operand is stored and the contents of the memory
locations in each of the addressing examples.
a) MOV [SI], AL
b) MOV [SI+BX+8], AH
c) MOV [BX]+300, DX
Now Examine the status of the CF, PF, AF, ZF, and SF if we execute the following statement after
first statement stated above. (N is equal to 123, convert to hex, show
binary equivalent of N and show all the carries generated at each stage of ad

Answer 1

Answer :- Given data :- The registers have the following values in hexadecimal cs = 1000 DS = 2000 1 SS = 3000 Bx = 8080 DI = 5000 SI = 4000 / CX=8791 AX = 25 FF BP = 7000 DX = 1299 AH AL Ах BH BL Вх Data registers CH C2 CX DH DL DX SD Pointer register Source Index BP SI DI Destination Index register Ax = AH, AL = AH = 25, AL = FF Вх BH, BL = 6080, BH = 60, BL = 80 = 8791, CH = 87, CL = 91 CX CH, CL DL - 99 DX DH, D2 = 1299, DH = 12, a) Mov (sil, AL Physical address of memory : DSX10 H +SI

(2000) x to + 4000 - 20000 4000 j 24000 is 2H000 The physical address of memory Mov (51) , AL The content of AL IS FF is moved to 24000 address. is 24000 Thus the physical address of memory and content of memory is FF, b) Mov [S1 + Bx +83 , AH physical address of memory : DS XI0H + SI+BX+8 (2000 x10) + 4000+ 6080 +8 20000 + 4000 + 6088 2A088 Mov (Sl+BX+8J ,AH The content of AH یا 25 is moved tol 2A088 memory location , Thus the physical address of memory is 24088 and content of memory is 25. Μον (Bx] + 300, DX Physical address of memory DSxlOH +Bx300

(2000 x 10 ) + 6080 +300 2000 o 7 6380 26380 moy (Bx 3 + 300 IDX is 1999 is moved to 26380 The content of DX memory location. is 26380 Thus the physical address memory and content of memory location is 1299. * After ejecuting Mov (51], AL The status of CF = o ; P = 0 , AF = 0, ZF = 0, 5FCO * After executing Mov (sit BX+8), AH The status SF=0 of CF =0, PF 20, AF - , ZF =0,