The instruction that is used to transfer the data from source operand to destination operand is
These instructions are used to copy and transfer the instructions.
Which of the following is not a data copy/transfer instruction?
DAS (Decimal Adjust after Subtraction) is an arithmetic instruction.
The instructions that involve various string manipulation operations are
The string instructions perform operations on strings such as load, move, scan, compare etc.
Which of the following instruction is not valid?
Both the source and destination operands cannot be memory locations except for string instructions.
In PUSH instruction, after each execution of the instruction, the stack pointer is
The actual current stack-top is always occupied by the previously pushed data. So, the push operation decrements SP by 2 and then stores the two bytes contents of the operand onto the stack.
The instruction that pushes the contents of the specified register/memory location on to the stack is
Since PUSH operation transfers data to stack from register or memory location.
In POP instruction, after each execution of the instruction, the stack pointer is
The actual current stack top is poped into the specific operand as the contents of stack top memory is stored in AL&SP and further contents of memory location pointed to by SP are copied to AH & SP.
The instructions that are used for reading an input port and writing an output port respectively are
The address of the input/output port may be specified directly or indirectly.
Example for input port: IN AX, DX ;This instruction reads data from a 16-bit port whose address is in DX and stores it in AX
Example for output port: OUT 03H, AL ;This sends data available in AL to a port whose address is 03H.
The instruction that is used for finding out the codes in case of code conversion problems is
The translate(XLAT) instruction is used to find codes.
The instruction that loads effective address formed by destination operand into the specified source register is
The instruction,LEA loads effective address and is more useful for assembly language rather than for machine language.
The flag that acts as Borrow flag in the instruction, SBB is
If borrow exists in the subtraction operation performed then carry flag is set.
In general, the source operand of an instruction can be
The source operand is the element which is data or data stored memory location on which operation is performed.
The instruction, CMP to compare source and destination operands it performs
For comparison, the instruction CMP subtracts source operand from destination operand.
Which instruction cannot force the 8086 processor out of ‘halt’ state?
Only an interrupt request or Reset will force the 8086 processor to come out of the ‘halt’ state.
NOP instruction introduces
NOP is the No operation. It means that the processor performs no operation for the clock cycle and thus there exists a delay.