INTRODUCTION TO MICROPROCESSOR Engr. Ammar Anwar Khan

TUTORIAL # 2 EE-353 Physical and Logical Addresses 2

MICROPROCESSOR

MEMORY 4

INSTRUCTION - MOV 5  MOV AX, BX  Mneunomincs  Move => MOV  Addition => ADD  Operands – Source, Destination  AX, BX etc or may be zero operand (e.g., HLT=> halt)

SEGMENT REGISTERS 6

ADDRESSES addresses are specified as xxxx:yyyy  where xxxx is value in segment register  yyyy is offset  Addresses are specified as relative to start of segment eg. Instruction Pointer relative to Code Segment

EXAMPLES 8  Logical Address  CS:IP, DS:IP, ES:IP, SS:SP  3000:1500  Physical Address (20 bits)  Shift Left CS, DS,ES or SS;  Add the result to IP or SP  =31500 is the Physical Address.

EXAMPLES 9  If CS=3000 and IP=1500  Offset =1500  Logical Address =3000:1500  Physical Address =31500  Lower range = =30000  Upper Range = FFFF=3FFFF

EXAMPLES 10  If SS=3500 and SP=FFEE  Offset =FFFE  Logical Address =3500:FFFE  Physical Address =44FFE  Lower range = =35000  Upper Range = FFFF=44FFF

STACK MEMORY 11  SS and SP  Used to store value on the RUN  PUSH => to store the value in the memory  POP => Take out the value from the memory  PUSH AX  POP AX 

STACK MEMORY 12

STACK MEMORY 13

LITTLE ENDIAN 14  Higher byte goes to Upper address  Lower byte goes to Lower address  MOV AX,6545  MOV [1500], AX  [1500] = 45  [1501] = 65  Same for stack !!!!!

FLAG REGISTER 15

DEBUG- COMMAND PROMPT 16

DEBUG- COMMAND PROMPT 17

DEBUG- COMMAND PROMPT 18

DEBUG- COMMAND PROMPT 19

DEBUG- COMMAND PROMPT 20

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