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
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)
Long
14(0/2)
14(0/2)
16(0/2)
22(2/2)
22(2/2)
24(2/2)
20(2/2)
20(2/2)
22(2/2)
NBCD
Byte
18(1/1)
18(1/1)
20(1/1)
24(3/1)
24(3/1)
26(3/1)
22(3/1)
22(3/1)
24(3/1)
NEG
Byte,
Word
16(1/1)
16(1/1)
18(2/2)
22(3/1)
22(3/1)
24(3/1)
20(3/1)
20(3/1)
22(3/1)
Long
24(2/2)
24(2/2)
26(2/2)
30(4/2)
30(4/2)
32(4/2)
28(4/2)
28(4/2)
30(4/2)
NEGX
Byte,
Word
16(1/1)
16(1/1)
18(2/2)
22(3/1)
22(3/1)
24(3/1)
20(3/1)
20(3/1)
22(3/1)
Long
24(2/2)
24(2/2)
26(2/2)
30(4/2)
30(4/2)
32(4/2)
28(4/2)
28(4/2)
30(4/2)
NOT
Byte,
Word
16(1/1)
16(1/1)
18(2/2)
22(3/1)
22(3/1)
24(3/1)
20(3/1)
20(3/1)
22(3/1)
Long
24(2/2)
24(2/2)
26(2/2)
30(4/2)
30(4/2)
32(4/2)
28(4/2)
28(4/2)
30(4/2)
TST
Byte,
Word
12(1/0)
12(1/0)
14(1/0)
18(3/0)
18(3/0)
20(3/0)
16(3/0)
16(3/0)
18(3/0)
Long
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
Size
Register
Memory*
ASR, ASL
Byte, Word
6+2n (1/0)
8(1/1)+
Long
8+2n (1/0)
—
LSR, LSL
Byte, Word
6+2n (1/0)
8(1/1)+
Long
8+2n (1/0)
—
ROR, ROL
Byte, Word
6+2n (1/0)
8(1/1)+
Long
8+2n (1/0)
—
ROXR, ROXL
Byte, Word
6+2n (1/0)
8(1/1)+
Long
8+2n (1/0)
—
+Add effective address calculation time.
n is the shift or rotate count.
* Word only.
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Freescale Semiconductor, Inc.
For More Information On This Product,
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