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Copy of 8086inst logical

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HarshitParkar6677

A microprocessor is an electronic component that is used by a computer to do its work. It is a central processing unit on a single integrated circuit chip containing millions of very small components including transistors, resistors, and diodes that work together. Some microprocessors in the 20th century required several chips. Microprocessors help to do everything from controlling elevators to searching the Web. Everything a computer does is described by instructions of computer programs, and microprocessors carry out these instructions many millions of times a second. [1] Microprocessors were invented in the 1970s for use in embedded systems. The majority are still used that way, in such things as mobile phones, cars, military weapons, and home appliances. Some microprocessors are microcontrollers, so small and inexpensive that they are used to control very simple products like flashlights and greeting cards that play music when you open them. A few especially powerful microprocessors are used in personal computers.

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Logical Instructions –These are the instructions used for basic logic operations such as AND, OR, NOT and XOR. –These are also used for carrying out bit by bit operations such as shift (SHR,SHL) or rotate (ROL,ROR,RCR,RCL). – One more Instruction under this category is TEST instruction.
AND (Logical AND) Syntax :-- AND destination, source • This instruction is used to bit by bit AND the contents of source to the destination. •The result is stored in the destination. •The source operand can be a immediate, a register or a memory location. •The destination can be a register or a memory location, but not an immediate data. •Both operands cannot be immediate data or memory location. •Flags affected : OF = 0 ,CF = 0 , AF is undefined. • And other flags (SF, ZF, PF) are affected based on the AND operation.
• Operation Performed :-- • Destination  Destination AND source • Examples :-- 1. AND BH,CL ;AND byte in CL with Byte in BH, result in BH. 2. AND BX,00FFH ;AND word in BX with immediate data 00ffH 3. AND [5000H], DX ;AND word in DX with a word in memory with offset 5000 in DS. AND (Logical AND) contd..
Numeric Example If AX = 3F0F, After Instruction, AND AX,9078H ; AX  AX AND 0008H ;AX  3F0F AND 0008 3F0F  0011 1111 0000 1111 AND 9078  1001 0000 0111 1000 ------------------------------------- = 0001 0000 0000 1000 1008H in AX register
OR (Logical OR) Syntax :-- OR destination, source • This instruction is used to bit by bit OR the contents of source to the destination. •The result is stored in the destination. •The source operand can be a immediate, a register or a memory location. •The destination can be a register or a memory location, but not an immediate data. •Both operands cannot be immediate data or memory location. •Flags affected : OF = 0 ,CF = 0 , AF is undefined. • And other flags (SF, ZF, PF) are affected based on the OR operation.
• Operation Performed :-- • Destination  Destination OR source • Examples :-- 1. OR BH,CL ;OR byte in CL with Byte in BH, result in BH. 2. OR BX,00FFH ;OR word in BX with immediate data 00ffH 3. OR [5000H], DX ; OR word in DX with a word in memory with offset 5000 in DS. OR (Logical OR) contd..
Numeric Example If AX = 3F0F, After Instruction, OR AX,9078H ; AX  AX OR 9078H ;AX  3F0F OR 9078 3F0F  0011 1111 0000 1111 OR 9078  1001 0000 0111 1000 ------------------------------------- = 1011 1111 0111 1111 BF7FH in AX register
XOR (Logical XOR) Syntax :-- XOR destination, source • This instruction is used to bit by bit XOR the contents of source to the destination. •The result is stored in the destination. •The source operand can be a immediate, a register or a memory location. •The destination can be a register or a memory location, but not an immediate data. •Both operands cannot be immediate data or memory location. •Flags affected : OF = 0 ,CF = 0 , AF is undefined. • And other flags (SF, ZF, PF) are affected based on the XOR operation.
• Operation Performed :-- • Destination  Destination XOR source • Examples :-- 1. XOR BH,CL ;XOR byte in CL with Byte in BH, result in BH. 2. XOR BX,00FFH ;XOR word in BX with immediate data 00ffH 3. XOR [5000H], DX ; XOR word in DX with a word in memory with offset 5000 in DS. XOR (Logical XOR) contd..
Numeric Example If AX = 3F0F, After Instruction, XOR AX,9078H ; AX  AX XOR 0008H ;AX  3F0F XOR 0008 3F0F  0011 1111 0000 1111 XOR 9078  1001 0000 0111 1000 ------------------------------------- = 1010 1111 0111 0111 AF77H in AX register
NOT (Logical Invert ) Syntax :-- NOT destination • This instruction complements (inverts) each bit of the byte or word stored in the destination. •The result is stored in the destination. •The destination can be a register or a memory location. •No Flags affected
• Operation Performed :-- • Destination  NOT Destination • Examples :-- 1. NOT BH ;Complement byte in BH, result in BH. 2. NOT BX ; Complement word in BX, result in BX. 3. NOT BYTE PTR [5000H] ; Complement byte in memory with offset 5000 in DS. NOT (Logical Invert ) contd..
Numeric Example If AX = 3F0F, After Instruction, NOT AX ; AX  NOT AX ;AX  NOT 3F0F 3F0F  0011 1111 0000 1111 Complement ------------------------------------- = 1100 0000 1111 0000 C0F0H in AX register
TEST (Logical compare ) Syntax :-- TEST destination, source • This instruction is used to bit by bit AND the contents of source to the destination. •The result is not stored in the destination. •The source operand can be a immediate, a register or a memory location. •The destination can be a register or a memory location, but not an immediate data. •Both operands cannot be immediate data or memory location. •Flags affected : OF = 0 ,CF = 0 , SF, ZF, PF. •TEST instruction is used to set flags before a conditional jump instruction
• Operation Performed :-- – Flags  set result of Destination AND source • Examples :-- 1. TEST BH,CL ;AND byte in CL with Byte in BH, no result but flags are affected. 2. TEST BX,00FFH ;AND word in BX with immediate data 00ffH, no result but flags are affected. 3. TEST DX, [5000H];AND word in DX with a word in memory with offset 5000 in DS, no result but flags are affected. TEST (Logical Compare) contd..
SHL / SAL (Shift Logical/Arithmetic Left) Syntax :-- SHL/SAL destination, count • SHL & SAL are the opcodes for the same operation •This instruction shifts the destination bit by bit to the left and insert zeroes in the newly introduced least significant bits. •The shift operation is through carry. •The count can be either 1 or specified by CL register. •The destination can be a byte or a word in register or a memory location, but not an immediate data. •Flags affected : OF ,CF, SF, ZF, PF. •These instructions can be used to multiply an unsigned number by power of 2.
CF BX 0 0 1 CF BX • Operation Performed :-- –CF  MSB ------------------ LSB  0 • Example :-- – If CF = 0, BX = E6D3H – After SAL BX, 1 ; Shift the contents of BX register by one towards left SHL / SAL (Shift Logical/Arithmetic Left)Cntd.. 1 1 1 0 0 1 1 0 1 1 0 1 0 0 1 1 1 1 0 0 1 1 0 1 1 0 1 0 0 1 1 0 BX = CDA6
• Example :-- • Use of SHL instruction for Multiplication:- – If CF = 0, BH = 04H – MOV CL, 03 ; Load CL register for the count – SHL BH, CL ; Shift the contents of BX register by one towards left – BH = 20H (32D) [ 04 * 23 = 32 D] – Note :-- SHL can be used to multiply a number with powers of 2. SHL / SAL (Shift Logical/Arithmetic Left)Cntd..
0 0 0 1 0 0 0 0 CF BH 0 0 0 0 0 0 0 SHL / SAL (Shift Logical/Arithmetic Left)Cntd.. BH = 20H with CF = 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0
SAR (Shift Arithmetic Right ) Syntax :-- SAR destination, count • This instruction shifts the destination bit by bit to the right and MSB position is kept in the old MSB position •The shift operation is through carry, LSB is shifted to CF. •The count can be either 1 or specified by CL register. •The destination can be a byte or a word in register or a memory location, but not an immediate data. •Flags affected : OF ,CF, SF, ZF, PF. •This instruction can be used to divide an unsigned number by power of 2.
BX CF 0 1 BX CF 1 1 1 1 0 0 1 1 0 1 1 0 1 0 0 1 • Operation Performed :-- – MSB ----------------- LSB  CF • Example :-- – If CF = 0, BX = E6D3H – After SAR BX, 1 ; Shift the contents of BX register by one towards right SAR (Shift Arithmetic Right)Cntd.. 1 1 1 0 0 1 1 0 1 1 0 1 0 0 1 1 BX = F369H
• Example :-- • Use of SAR instruction for Division:- – If CF = 0, BH = 14H – MOV CL, 02 ; Load CL register for the count – SAR BH, CL ; Shift the contents of BX register by one towards right – BH = 05H (20D) [ 20 / 22 = 5D] – Note :-- SAR can be used to divide a number with powers of 2 and get the quotient. SAR (Shift Arithmetic Right )Cntd..
0 0 0 0 0 1 0 1 BH CF 0 0 0 SAR (Shift Arithmetic Right)Cntd.. BH = 05H with CF = 0 0 0 0 1 0 1 0 0 0 0 0 0 1 0 1 0
SHR (Shift Logical Right) Syntax :-- SHR destination, count •This instruction shifts the destination bit by bit to the right and insert zeroes in the newly introduced most significant bits. •The shift operation is through carry. •The count can be either 1 or specified by CL register. •The destination can be a byte or a word in register or a memory location, but not an immediate data. •Flags affected : OF ,CF, SF, ZF, PF.
1 1 1 1 0 0 1 1 0 1 1 0 1 0 0 1 BX CF 0 0 1 BX CF • Operation Performed :-- –0  MSB ------------------ LSB  CF • Example :-- – If CF = 0, BX = E6D3H – After SHR BX, 1 ; Shift the contents of BX register by one towards right SHR (Shift Logical Right)Cntd.. 1 1 1 0 0 1 1 0 1 1 0 1 0 0 1 1 BX = F369H

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Copy of 8086inst logical

  • 1. Logical Instructions –These are the instructions used for basic logic operations such as AND, OR, NOT and XOR. –These are also used for carrying out bit by bit operations such as shift (SHR,SHL) or rotate (ROL,ROR,RCR,RCL). – One more Instruction under this category is TEST instruction.
  • 2. AND (Logical AND) Syntax :-- AND destination, source • This instruction is used to bit by bit AND the contents of source to the destination. •The result is stored in the destination. •The source operand can be a immediate, a register or a memory location. •The destination can be a register or a memory location, but not an immediate data. •Both operands cannot be immediate data or memory location. •Flags affected : OF = 0 ,CF = 0 , AF is undefined. • And other flags (SF, ZF, PF) are affected based on the AND operation.
  • 3. • Operation Performed :-- • Destination  Destination AND source • Examples :-- 1. AND BH,CL ;AND byte in CL with Byte in BH, result in BH. 2. AND BX,00FFH ;AND word in BX with immediate data 00ffH 3. AND [5000H], DX ;AND word in DX with a word in memory with offset 5000 in DS. AND (Logical AND) contd..
  • 4. Numeric Example If AX = 3F0F, After Instruction, AND AX,9078H ; AX  AX AND 0008H ;AX  3F0F AND 0008 3F0F  0011 1111 0000 1111 AND 9078  1001 0000 0111 1000 ------------------------------------- = 0001 0000 0000 1000 1008H in AX register
  • 5. OR (Logical OR) Syntax :-- OR destination, source • This instruction is used to bit by bit OR the contents of source to the destination. •The result is stored in the destination. •The source operand can be a immediate, a register or a memory location. •The destination can be a register or a memory location, but not an immediate data. •Both operands cannot be immediate data or memory location. •Flags affected : OF = 0 ,CF = 0 , AF is undefined. • And other flags (SF, ZF, PF) are affected based on the OR operation.
  • 6. • Operation Performed :-- • Destination  Destination OR source • Examples :-- 1. OR BH,CL ;OR byte in CL with Byte in BH, result in BH. 2. OR BX,00FFH ;OR word in BX with immediate data 00ffH 3. OR [5000H], DX ; OR word in DX with a word in memory with offset 5000 in DS. OR (Logical OR) contd..
  • 7. Numeric Example If AX = 3F0F, After Instruction, OR AX,9078H ; AX  AX OR 9078H ;AX  3F0F OR 9078 3F0F  0011 1111 0000 1111 OR 9078  1001 0000 0111 1000 ------------------------------------- = 1011 1111 0111 1111 BF7FH in AX register
  • 8. XOR (Logical XOR) Syntax :-- XOR destination, source • This instruction is used to bit by bit XOR the contents of source to the destination. •The result is stored in the destination. •The source operand can be a immediate, a register or a memory location. •The destination can be a register or a memory location, but not an immediate data. •Both operands cannot be immediate data or memory location. •Flags affected : OF = 0 ,CF = 0 , AF is undefined. • And other flags (SF, ZF, PF) are affected based on the XOR operation.
  • 9. • Operation Performed :-- • Destination  Destination XOR source • Examples :-- 1. XOR BH,CL ;XOR byte in CL with Byte in BH, result in BH. 2. XOR BX,00FFH ;XOR word in BX with immediate data 00ffH 3. XOR [5000H], DX ; XOR word in DX with a word in memory with offset 5000 in DS. XOR (Logical XOR) contd..
  • 10. Numeric Example If AX = 3F0F, After Instruction, XOR AX,9078H ; AX  AX XOR 0008H ;AX  3F0F XOR 0008 3F0F  0011 1111 0000 1111 XOR 9078  1001 0000 0111 1000 ------------------------------------- = 1010 1111 0111 0111 AF77H in AX register
  • 11. NOT (Logical Invert ) Syntax :-- NOT destination • This instruction complements (inverts) each bit of the byte or word stored in the destination. •The result is stored in the destination. •The destination can be a register or a memory location. •No Flags affected
  • 12. • Operation Performed :-- • Destination  NOT Destination • Examples :-- 1. NOT BH ;Complement byte in BH, result in BH. 2. NOT BX ; Complement word in BX, result in BX. 3. NOT BYTE PTR [5000H] ; Complement byte in memory with offset 5000 in DS. NOT (Logical Invert ) contd..
  • 13. Numeric Example If AX = 3F0F, After Instruction, NOT AX ; AX  NOT AX ;AX  NOT 3F0F 3F0F  0011 1111 0000 1111 Complement ------------------------------------- = 1100 0000 1111 0000 C0F0H in AX register
  • 14. TEST (Logical compare ) Syntax :-- TEST destination, source • This instruction is used to bit by bit AND the contents of source to the destination. •The result is not stored in the destination. •The source operand can be a immediate, a register or a memory location. •The destination can be a register or a memory location, but not an immediate data. •Both operands cannot be immediate data or memory location. •Flags affected : OF = 0 ,CF = 0 , SF, ZF, PF. •TEST instruction is used to set flags before a conditional jump instruction
  • 15. • Operation Performed :-- – Flags  set result of Destination AND source • Examples :-- 1. TEST BH,CL ;AND byte in CL with Byte in BH, no result but flags are affected. 2. TEST BX,00FFH ;AND word in BX with immediate data 00ffH, no result but flags are affected. 3. TEST DX, [5000H];AND word in DX with a word in memory with offset 5000 in DS, no result but flags are affected. TEST (Logical Compare) contd..
  • 16. SHL / SAL (Shift Logical/Arithmetic Left) Syntax :-- SHL/SAL destination, count • SHL & SAL are the opcodes for the same operation •This instruction shifts the destination bit by bit to the left and insert zeroes in the newly introduced least significant bits. •The shift operation is through carry. •The count can be either 1 or specified by CL register. •The destination can be a byte or a word in register or a memory location, but not an immediate data. •Flags affected : OF ,CF, SF, ZF, PF. •These instructions can be used to multiply an unsigned number by power of 2.
  • 17. CF BX 0 0 1 CF BX • Operation Performed :-- –CF  MSB ------------------ LSB  0 • Example :-- – If CF = 0, BX = E6D3H – After SAL BX, 1 ; Shift the contents of BX register by one towards left SHL / SAL (Shift Logical/Arithmetic Left)Cntd.. 1 1 1 0 0 1 1 0 1 1 0 1 0 0 1 1 1 1 0 0 1 1 0 1 1 0 1 0 0 1 1 0 BX = CDA6
  • 18. • Example :-- • Use of SHL instruction for Multiplication:- – If CF = 0, BH = 04H – MOV CL, 03 ; Load CL register for the count – SHL BH, CL ; Shift the contents of BX register by one towards left – BH = 20H (32D) [ 04 * 23 = 32 D] – Note :-- SHL can be used to multiply a number with powers of 2. SHL / SAL (Shift Logical/Arithmetic Left)Cntd..
  • 19. 0 0 0 1 0 0 0 0 CF BH 0 0 0 0 0 0 0 SHL / SAL (Shift Logical/Arithmetic Left)Cntd.. BH = 20H with CF = 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0
  • 20. SAR (Shift Arithmetic Right ) Syntax :-- SAR destination, count • This instruction shifts the destination bit by bit to the right and MSB position is kept in the old MSB position •The shift operation is through carry, LSB is shifted to CF. •The count can be either 1 or specified by CL register. •The destination can be a byte or a word in register or a memory location, but not an immediate data. •Flags affected : OF ,CF, SF, ZF, PF. •This instruction can be used to divide an unsigned number by power of 2.
  • 21. BX CF 0 1 BX CF 1 1 1 1 0 0 1 1 0 1 1 0 1 0 0 1 • Operation Performed :-- – MSB ----------------- LSB  CF • Example :-- – If CF = 0, BX = E6D3H – After SAR BX, 1 ; Shift the contents of BX register by one towards right SAR (Shift Arithmetic Right)Cntd.. 1 1 1 0 0 1 1 0 1 1 0 1 0 0 1 1 BX = F369H
  • 22. • Example :-- • Use of SAR instruction for Division:- – If CF = 0, BH = 14H – MOV CL, 02 ; Load CL register for the count – SAR BH, CL ; Shift the contents of BX register by one towards right – BH = 05H (20D) [ 20 / 22 = 5D] – Note :-- SAR can be used to divide a number with powers of 2 and get the quotient. SAR (Shift Arithmetic Right )Cntd..
  • 23. 0 0 0 0 0 1 0 1 BH CF 0 0 0 SAR (Shift Arithmetic Right)Cntd.. BH = 05H with CF = 0 0 0 0 1 0 1 0 0 0 0 0 0 1 0 1 0
  • 24. SHR (Shift Logical Right) Syntax :-- SHR destination, count •This instruction shifts the destination bit by bit to the right and insert zeroes in the newly introduced most significant bits. •The shift operation is through carry. •The count can be either 1 or specified by CL register. •The destination can be a byte or a word in register or a memory location, but not an immediate data. •Flags affected : OF ,CF, SF, ZF, PF.
  • 25. 1 1 1 1 0 0 1 1 0 1 1 0 1 0 0 1 BX CF 0 0 1 BX CF • Operation Performed :-- –0  MSB ------------------ LSB  CF • Example :-- – If CF = 0, BX = E6D3H – After SHR BX, 1 ; Shift the contents of BX register by one towards right SHR (Shift Logical Right)Cntd.. 1 1 1 0 0 1 1 0 1 1 0 1 0 0 1 1 BX = F369H