
560
APPENDIX B Instructions
Note:
The execution cycle count found when an overflow occurs in a DIV or DIVW instruction may
be a pre-operation count or a post-operation count depending on the detection timing.
When an overflow occurs with DIV or DIVW instruction, the contents of the AL are destroyed.
"Cycle Count Correction Values for Counting Execution Cycles" for information on (a) to (d)
in the table.
MUL
MULW
A
A,ear
A,eam
A
A,ear
A,eam
2
2+
2
2+
*8
*9
*10
*11
*12
*13
0
1
0
1
0
(b)
0
(c)
byte (AH) * byte (AL) --> word (A)
byte (A) * byte (ear) --> word (A)
byte (A) * byte (eam) --> word (A)
word (AH) * word (AL) --> Long (A)
word (A) * word (ear) --> Long (A)
word (A) * word (eam) --> Long (A)
-
*1: 3: Division by 0, 8 or 18: Overflow, 18: Normal
*2: 4: Division by 0, 11 or 22: Overflow, 23: Normal
*3: 5+(a): Division by 0, 12+(a) or 23+(a): Overflow, 24+(a): Normal
*4: When dividend is positive; 4: Division by 0, 12 or 30: Overflow, 31: Normal
When dividend is negative; 4: Division by 0, 12 or 31: Overflow, 32: Normal
*5: When dividend is positive; 5+(a): Division by 0, 12+(a) or 31+(a): Overflow, 32+(a): Normal
When dividend is negative; 5+(a): Division by 0, 12+(a) or 32+(a): Overflow, 33+(a): Normal
*6: (b): Division by 0 or overflow, 2 x (b): Normal
*7: (c): Division by 0 or overflow, 2 x (c): Normal
*8: 3: Byte (AH) is 0, 12: result is positive, 13: result is negative
*9: 4: Byte (ear) is 0, 13: result is positive, 14: result is negative
*10: 5+(a): Byte (eam) is 0, 14+(a): result is positive, 15+(a): result is negative
*11: 3: Word(AH) is 0, 16: result is positive, 19: result is negative
*12: 4: Word(ear) is 0, 17: result is positive, 20: result is negative
*13: 5+(a): Word(eam) is 0, 18+(a): result is positive, 21+(a): result is negative
Table B.8-7 11 Signed Multiplication/Division Instructions (word, long word)
Mnemonic
#
RG
B
Operation
L
H
A
H
I
S
TN
ZV
C
R
M
W