Instruction Set
4-113
JNO
Jump If Not Overflow
JNO
What It Does
If the previous instruction clears the Overflow Flag (OF), JNO stops executing the current
sequence of instructions and begins executing a new sequence of instructions; otherwise,
execution continues with the next instruction.
Syntax
Description
JNO tests the flag set by a previous instruction. If the given condition is true (OF=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
JNO
rel8
71
cb
Jump short if not overflow (OF=0)
13,4
13,4
JNO
label
To jump if the result of a previous
operation cleared OF to 0, use JNO.
if (OF == 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...