Computer Hardware User's Manual

3-20 Vol. 2A AAA—ASCII Adjust After Addition
INSTRUCTION SET REFERENCE, A-M
Protected Mode Exceptions
#UD If the LOCK prefix is used.
Real-Address Mode Exceptions
Same exceptions as protected mode.
Virtual-8086 Mode Exceptions
Same exceptions as protected mode.
Compatibility Mode Exceptions
Same exceptions as protected mode.
64-Bit Mode Exceptions
#UD If in 64-bit mode.