Instruction Set
4-107
JNE
Jump If Not Equal
JNE
JNZ
Jump If Not Zero
What It Does
If the previous instruction clears the Zero Flag (ZF), JNE and JNZ stop executing the current
sequence of instructions and begin executing a new sequence of instructions; otherwise,
execution continues with the next instruction.
Syntax
Description
JNE and JNZ test the flag set by a previous instruction. If the given condition is true (ZF=0),
a short jump is made to the location provided as the operand.
Operation It Performs
Flag Settings After Instruction
Form
Opcode
Description
Clocks
Am186 Am188
JNE
rel8
75
cb
Jump short if not equal (ZF=0)
13,4
13,4
JNZ
rel8
75
cb
Jump short if not zero (ZF=0)
13,4
13,4
JNE
label
To jump if the result of a previous integer
comparison was not equal, use JNE or
its synonym, JNZ. Both forms perform
the same operation.
JNZ
label
if (ZF == 0)
{
/* extend sign of label */
if (
label < 0)
displacement = 0xFF00 |
label;
else
displacement = 0x00FF &
label;
/* branch to labeled instruction */
IP = IP + displacement;
}
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Processor Status
Flags Register
reserved
OF DF
IF TF SF ZF
AF
PF
CF
? = undefined; – = unchanged
–
–
–
–
–
– res – res – res –
Содержание Am186 Series
Страница 1: ...Am186 and Am188 Family Instruction Set Manual February 1997...
Страница 10: ...Table of Contents x...
Страница 18: ...Programming 1 8...
Страница 40: ...Instruction Set Listing 3 14...