Category: 8086 INSTRUCTION SET

8086 String Instructions

8086 String Instructions: The 8086 String Instructions are namely, REP/REPE/REPZ/REPNE/REPNZ MOVS/MOVSB/MOVSN CMPS/CMPSB/CMPSW SCAS/SCASB/SCASW LODS/LODSB/LODSW STOS/STOSB/STOSW REP/REPE/REPZ/REPNE/REPNZ Instruction : REP is a prefix which is written before one of the 8086 String Instructions. These instructions repeat until specified condition exists. MOVS/MOVSB/MOVSW Instruction : This instruction copies a byte or word from a location in the data segment […]

8086 Processor Control Instruction

8086 Processor Control Instruction: The 8086 Processor Control Instruction are namely, STC CLC CMC STD CLD STI CLI STC Instruction : This instruction sets the carry flag, STC does not affect any other flag. CLC Instruction : This instruction resets the carry flag to zero. CLC does not affect any other flag. CMC Instruction : This […]

8086 Program Execution Transfer Instructions

8086 Program Execution Transfer Instructions: The 8086 Program Execution Transfer Instructions are namely a) Unconditional transfer instructions: CALL RET JMP J cond CALL Instruction : The CALL instruction is used to 8086 Program Execution Transfer Instructions to a subprogram or procedure. There are two basic types of CALLs, near and far. A near CALL is a […]

8086 Rotate Instructions

8086 Rotate Instructions: The 8086 Rotate Instructions are namely ROL ROR RCL RCR ROL Instruction : ROL destination, count. This 8086 Rotate Instructions all bits in a specified byte or word to the left some number of bit positions. MSB is placed as a new LSB and a new CF. Diagram shows ROL instruction for byte […]

8086 Shift Instructions

8086 Shift Instructions: The 8086 Shift Instructions are follows SAL/SHL SHR SAR SAL/SHL Instruction : SAL/SHL destination, count. SAL and SHL are two mnemonics for the same instruction. This instruction shifts each bit in the specified destination to the left and 0 is stored at LSB position. The MSB is shifted into the carry flag. The […]