SBB: Subtract  with Borrow  :- The subtract with borrow instruction subtracts the source operand and the borrow flag (CF) which might reflect the result of the past calculations, from the destination operand. Subtraction along with the borrow, here means subtracting value 1 from the subtraction obtained by SUB, if carry (borrow) flag is the set.

The result is stored in the destination operand. All the flags are affected (Condition code) by this instruction. The instance of this instruction is following:

Example :

1. SBB        O100H                Immediate [destination AX]

2. SBB        AX.BX                  Register

3. SBB        AX, [5000H]         Direct

4. SBB        [5000H], 0100      Immediate