Specifications

MICROPROCESSADORES
CONJUNTO DE INSTRUÇÕES DO 8086
4
Luís Miguel Charrua Figueiredo 4 - 1 E.N.I.D.H.
Conjunto de
Instruções do 8086
Instruções detalhadas
AAA - Ascii Adjust for Addition
Usage: AAA
Modifies flags: AF CF (OF,PF,SF,ZF undefined)
Changes contents of AL to valid unpacked decimal. The
high order nibble is zeroed.
AAD - Ascii Adjust for Division
Usage: AAD
Modifies flags: SF ZF PF (AF,CF,OF undefined)
Used before dividing unpacked decimal numbers.
Multiplies AH by 10 and the adds result into AL. Sets AH
to zero. This instruction is also known to have an
undocumented behavior.
AL := 10*AH+AL
AH := 0
AAM - Ascii Adjust for Multiplication
Usage: AAM
Modifies flags: PF SF ZF (AF,CF,OF undefined)
AH := AL / 10
AL := AL mod 10
Used after multiplication of two unpacked decimal
numbers, this instruction adjusts an unpacked decimal
number. The high order nibble of each byte must be
zeroed before using this instruction. This instruction is
also known to have an undocumented behavior.
AAS - Ascii Adjust for Subtraction
Usage: AAS
Modifies flags: AF CF (OF,PF,SF,ZF undefined)
Corrects result of a previous unpacked decimal
subtraction in AL. High order nibble is zeroed.
ADC - Add With Carry
Usage: ADC dest,src
Modifies flags: AF CF OF SF PF ZF
Sums two binary operands placing the result in the
destination. If CF is set, a 1 is added to the destination.
ADD - Arithmetic Addition
Usage: ADD dest,src
Modifies flags: AF CF OF PF SF ZF
Adds "src" to "dest" and replacing the original contents of
"dest". Both operands are binary.
AND - Logical And
Usage: AND dest,src
Modifies flags: CF OF PF SF ZF (AF undefined)
Performs a logical AND of the two operands replacing the
destination with the result.
CALL - Procedure Call
Usage: CALL destination
Modifies flags: None
Pushes Instruction Pointer (and Code Segment for far
calls) onto stack and loads Instruction Pointer with the
address of proc-name. Code continues with execution at
CS:IP.
CBW - Convert Byte to Word
Usage: CBW
Modifies flags: None
Converts byte in AL to word Value in AX by extending
sign of AL throughout register AH.
CLC - Clear Carry
Usage: CLC
Modifies flags: CF
Clears the Carry Flag.
CLD - Clear Direction Flag
Usage: CLD
Modifies flags: DF
Clears the Direction Flag causing string instructions to
increment the SI and DI index registers.
CLI - Clear Interrupt Flag (disable)
Usage: CLI
Modifies flags: IF