Instruction queue is six byte long and stores the pre-fetched instructions from the Code Segment. From there, the instruction is taken to the instruction decoder, where it is decoded. The decoder passes the described information to the timing and control unit, where it generates various control signals to execute the instruction.
The BIU has the First in First out (FIFO) group of register called queue. To speed up the execution, the BIU fetches as many as six instruction bytes ahead of time from memory these pre-fetched instruction bytes are held for the execution unit is a group of register called queue. The EU simply reads the instruction from the queue of BIU when it’s ready for next instruction. It simply reads the instruction bytes for…show more content… Find the physical address in following instruction.
MOV AL, [BP]
MOV CX, [BX]
MOV AL, [BP+SI]
MOV CS: [BX], AL
Solution:
MOV AL, [BP] - This instruction copies a byte from memory location to the AL register.
The base address of memory location will be=SS*10=30000 H
The physical address of memory will be= 30000 +0010 H=30010 H
MOV CX, [BX] - This instruction copies a word from memory location to the CX register.
The base address of memory location will be=DS*10=20000 H
The physical address of memory will be= 20000 +0020 H=20020 H
MOV AL, [BP+SI] - This instruction copies a byte from memory location to the AL register.
The base address will be the summation of the contents of BP and SI=0010+0040=0050 H
The base address of segment will be=SS*10=30000 H
The physical address of memory will be= 30000 +0050 H=30050 H
MOV CS: [BX], AL - This instruction copies a byte AL register to memory location.
The base address of segment will be=CS*10=10000 H
The physical address of memory will be= 10000 +0020 H=10020
