A-16
OPCODE MAP
Table A-12 shows the opcode map if the accompanying ModR/M byte is outside the range of
00H to BFH. In this case the first digit of the ModR/M byte selects the row in the table and the
second digit selects the column.
Table A-12. DA Opcode Map When ModR/M Byte is Outside 00H to BFH
1
NOTE:
1.All blanks in the opcode map are reserved and should not be used. Do not depend on the operation of
these undefined opcodes.
A.2.6.6.ESCAPE OPCODES WITH DB AS FIRST BYTE
Table A-13 and A-14 contain the opcodes maps for the escape instruction opcodes that begin
with DBH. Table A-13 shows the opcode map if the accompanying ModR/M byte within the
range of 00H through BFH. Here, the value of bits 5, 4, and 3 (the nnn field in Figure A-1) se-
lects the instruction.
0
1
2
3
4
5
7
C
FCMOVB
ST(0),ST(0)ST(0),ST(1)ST(0),ST(2)ST(0),ST(3)ST(0),ST(4)ST(0),ST(5)ST(0),ST(6)ST(0),ST(7)
D
FCMOVBE
ST(0),ST(0)ST(0),ST(1)ST(0),ST(2)ST(0),ST(3)ST(0),ST(4)ST(0),ST(5)ST(0),ST(6)ST(0),ST(7)
E
F
8
9
A
B
C
D
E
F
C
FCMOVE
ST(0),ST(0)ST(0),ST(1)ST(0),ST(2)ST(0),ST(3)ST(0),ST(4)ST(0),ST(5)ST(0),ST(6)ST(0),ST(7)
D
FCMOVU
ST(0),ST(0)ST(0),ST(1)ST(0),ST(2)ST(0),ST(3)ST(0),ST(4)ST(0),ST(5)ST(0),ST(6)ST(0),ST(7)
E
FUCOMPP
F
