Intel IA-32 Manuel D’Utilisation
15-8 Vol. 3A
8086 EMULATION
Table 15-1. Real-Address Mode Exceptions and Interrupts
Vector
No.
Description
Real-Address
Mode
Virtual-8086
Mode
Intel 8086
Processor
0
Divide Error (#DE)
Yes
Yes
Yes
1
Debug Exception (#DB)
Yes
Yes
No
2
NMI Interrupt
Yes
Yes
Yes
3
Breakpoint (#BP)
Yes
Yes
Yes
4
Overflow (#OF)
Yes
Yes
Yes
5
BOUND Range Exceeded (#BR)
Yes
Yes
Reserved
6
Invalid Opcode (#UD)
Yes
Yes
Reserved
7
Device Not Available (#NM)
Yes
Yes
Reserved
8
Double Fault (#DF)
Yes
Yes
Reserved
9
(Intel reserved. Do not use.)
Reserved
Reserved
Reserved
10
Invalid TSS (#TS)
Reserved
Yes
Reserved
11
Segment Not Present (#NP)
Reserved
Yes
Reserved
12
Stack Fault (#SS)
Yes
Yes
Reserved
13
General Protection (#GP)*
Yes
Yes
Reserved
14
Page Fault (#PF)
Reserved
Yes
Reserved
15
(Intel reserved. Do not use.)
Reserved
Reserved
Reserved
16
Floating-Point Error (#MF)
Yes
Yes
Reserved
17
Alignment Check (#AC)
Reserved
Yes
Reserved
18
Machine Check (#MC)
Yes
Yes
Reserved
19-31
(Intel reserved. Do not use.)
Reserved
Reserved
Reserved
32-255
User Defined Interrupts
Yes
Yes
Yes
NOTE:
* In the real-address mode, vector 13 is the segment overrun exception. In protected and virtual-8086
modes, this exception covers all general-protection error conditions, including traps to the virtual-
8086 monitor from virtual-8086 mode.
8086 monitor from virtual-8086 mode.