9-8
M68000 8-/16-/32-BIT MICROPROCESSORS USER'S MANUAL
MOTOROLA
Table 9-11. Single Operand Instruction Loop Mode Execution Times
Loop Continued
Loop Terminated
Valid Count, cc False
Valid Count, cc True
Expired Count
Instruction
Size
(An)
(An)+
–(An)
(An)
(An)+
–(An)
(An)
(An)+
–(An)
CLR
Byte,
Word
Long
Byte
Byte,
Word
Long
Byte,
Word
Long
Byte,
Word
Long
Byte,
Word
Long
10
(0/1)
10
(0/1)
12
(0/1)
18
(2/1)
18
(2/1)
20
(2/0)
16
(2/1)
16
(2/1)
18
(2/1)
14
(0/2)
18
(1/1)
16
(1/1)
14
(0/2)
18
(1/1)
16
(1/1)
16
(0/2)
20
(1/1)
18
(2/2)
22
(2/2)
24
(3/1)
22
(3/1)
22
(2/2)
24
(3/1)
22
(3/1)
24
(2/2)
26
(3/1)
24
(3/1)
20
(2/2)
22
(3/1)
20
(3/1)
20
(2/2)
22
(3/1)
20
(3/1)
22
(2/2)
24
(3/1)
22
(3/1)
NBCD
NEG
24
(2/2)
16
(1/1)
24
(2/2)
16
(1/1)
26
(2/2)
18
(2/2)
30
(4/2)
22
(3/1)
30
(4/2)
22
(3/1)
32
(4/2)
24
(3/1)
28
(4/2)
20
(3/1)
28
(4/2)
20
(3/1)
30
(4/2)
22
(3/1)
NEGX
24
(2/2)
16
(1/1)
24
(2/2)
16
(1/1)
26
(2/2)
18
(2/2)
30
(4/2)
22
(3/1)
30
(4/2)
22
(3/1)
32
(4/2)
24
(3/1)
28
(4/2)
20
(3/1)
28
(4/2)
20
(3/1)
30
(4/2)
22
(3/1)
NOT
24
(2/2)
12
(1/0)
24
(2/2)
12
(1/0)
26
(2/2)
14
(1/0)
30
(4/2)
18
(3/0)
30
(4/2)
18
(3/0)
32
(4/2)
20
(3/0)
28
(4/2)
16
(3/0)
28
(4/2)
16
(3/0)
30
(4/2)
18
(3/0)
TST
18
(2/0)
18
(2/0)
20
(2/0)
24
(4/0)
24
(4/0)
26
(4/0)
20
(4/0)
20
(4/0)
22
(4/0)
9.6 SHIFT/ROTATE INSTRUCTION EXECUTION TIMES
Tables 9-12 and 9-13 list the timing data for the shift and rotate instructions. The total
number of clock periods, the number of read cycles, and the number of write cycles are
shown in the previously described format. The number of clock periods, the number of
read cycles, and the number of write cycles, respectively, must be added to those of the
effective address calculation where indicated by a plus sign (+).
Table 9-12. Shift/Rotate Instruction Execution Times
Instruction
ASR, ASL
Size
Register
6+2n
(1/0)
8+2n
(1/0)
6+2n
(1/0)
8+2n
(1/0)
6+2n
(1/0)
8+2n
(1/0)
6+2n
(1/0)
8+2n
(1/0)
Memory*
8
(1/1)+
—
8
(1/1)+
—
8
(1/1)+
—
8
(1/1)+
—
Byte, Word
Long
Byte, Word
Long
Byte, Word
Long
Byte, Word
Long
LSR, LSL
ROR, ROL
ROXR, ROXL
+Add effective address calculation time.
n is the shift or rotate count.
* Word only.