NOT Instruction

The NOT instruction toggles (complements) all bits in an operand.

NOT — One's Complement Negation (Logical NOT)

Usage: NOT dest

Flag O D I S Z A P C
Result                

Inverts the bits of the “dest” operand forming the 1's complement.
Clocks
Operands 286 386 486 Size Bytes
reg 2 2 1 2
mem 7 6 3 2-4

NEG performs two's complement, which changes a binary value from positive to negative and vice versa by reversing the bits and adding 1. Typically, NOT is used on unsigned data and NEG on signed data.

 NOT   NEG   Setting Zero Flag  


 .code


 mov   eax, 0


 mov   al, 00111010b


 not   al


 call  WriteHex
 


 .code


 mov   eax, 0


 mov   al, 00111010b


 neg   al


 call  WriteHex
 


 .code


     and   al, 0


     jz    L1


     call  WaitMsg


 L1: exit
 Output  Output  Output
   



   



   



 Clearing Sign Flag   Setting Overflow Flag   Setting/Clearing Carry Flag  


 .code


     and   al, 7Fh


     js    L1


     call  WaitMsg


 L1: exit
 


 .code


     mov   al, 7Fh


     inc   al


     jo    L1


     call  WaitMsg


 L1: exit
 


 .code


     stc   ; or clc


     jc    L1


     call  WaitMsg


 L1: exit
 Output  Output  Output
   



   



   





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