Unsigned Conditional Jump Instructions 

Conditional jump instructions for unsigned comparisons deal with numbers that are positive numbers only. The following table shows the condition flags used in unsigned comparison and their meanings.

Flags Meaning
ZF = 1 equality
ZF = 0 inequality
CF = 1 A < B
CF = 0 A > B

Note that if number A is less than number B, there will be a borrow when B is subtracted from A. This will set the CF to 1 to indicate that there was a borrow. However, if A is greater than B, there will be no borrow and hence CF=0.

The following table shows all possible conditional jump instructions for unsigned number comparisons. The table also shows the flags condition for a jump to be taken.

Instruction Equivalent Meaning (jump if) Condition
JA JNBE Above (not below or equal) CF = 0 and ZF = 0
JAE JNB Above or equal (not below) CF = 0
JB JNAE Below (not above or equal) CF = 1
JBE JNA Below or equal (not above) CF = 1 or ZF = 1
JE JZ Equal (zero) ZF = 1
JNE JNZ Not equal (not zero) ZF = 0