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MOTOROLA
M68000 8-/16-/32-BIT MICROPROCESSORS USER'S MANUAL
10-25
Num
Characteristic
8 MHz
10 MHz
12.5 MHz
16.67 MHz
20 MHz
Unit
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
29
AS, DS
Negated to Data-In Invalid
(Hold Time on Read)
0
—
0
—
0
—
0
—
0
—
ns
29A
AS, DS
Negated to Data-In High
Impedance
—
187
—
150
—
120
—
90
—
75
ns
30
AS, DS
Negated to
BERR
Negated
0
—
0
—
0
—
0
—
0
—
ns
312,5
DTACK
Asserted to Data-In Valid
(Setup Time)
—
90
—
65
—
50
—
50
—
42
ns
32
HALT
and
RESET
Input Transition
Time
0
150
0
150
0
150
0
150
0
150
ns
33
Clock High to
BG
Asserted
—
35
—
35
—
35
0
30
0
25
ns
34
Clock High to
BG
Negated
—
35
—
35
—
35
0
30
0
25
ns
35
367
BR
Asserted to
BG
Asserted
1.5
3.5
1.5
3.5
1.5
3.5
1.5
3.5
1.5
3.5
Clks
BR
Negated to
BG
Negated
1.5
3.5
1.5
3.5
1.5
3.5
1.5
3.5
1.5
3.5
Clks
38
BG
Asserted to Control, Address,
Data Bus High Impedance (
AS
Negated)
—
55
—
55
—
55
—
50
—
42
ns
39
BG
Width Negated
1.5
1.5
1.5
1.5
1.5
—
Clks
44
475
482,3
AS, DS
Negated to
VPA
Negated
0
55
0
55
0
55
0
50
0
42
ns
Asynchronous Input Setup Time
5
—
5
—
5
—
5
—
5
—
ns
BERR
Asserted to
DTACK
Asserted
20
—
20
—
20
—
10
—
10
—
ns
53
Data-Out Hold from Clock High
0
—
0
—
0
—
0
—
0
—
ns
55
R/
W
Asserted to Data Bus
Impedance Change
30
—
20
—
10
—
0
—
0
—
ns
564
587
HALT/RESET
Pulse Width
10
—
10
—
10
—
10
—
10
—
Clks
BR
Negated to
AS, DS
, R/
W
Driven
1.5
—
1.5
—
1.5
—
1.5
—
1.5
—
Clks
58A7
BR
Negated to FC,
VMA
Driven
1
—
1
—
1
—
1
—
1
—
Clks
NOTES:1. For a loading capacitance of less than or equal to 50 pF, subtract 5 ns from the value given in the
maximum columns.
2. Actual value depends on clock period.
3.I f #47 is satisfied for both
DTACK
and
BERR
, #48 may be ignored. In the absence of
DTACK, BERR
is an
asynchronous input using the asynchronous input setup time (#47).
4. For power-up, the MC68EC000 must be held in the reset state for 520 clocks to allow stabilization of on-
chip circuitry. After the system is powered up, #56 refers to the minimum pulse width required to
reset the processor.
5. If the asynchronous input setup time (#47) requirement is satisfied for
DTACK
, the
DTACK
-asserted to data
setup time (#31) requirement can be ignored. The data must only satisfy the data-in to clock low
setup time (#27) for the following clock cycle.
6. When
AS
and R/
W
are equally loaded (
±
20;pc), subtract 5 ns from the values given in these columns.
7. The minimum value must be met to guarantee proper operation. If the maximum value is exceeded,
BG
may be reasserted.
8.
DS
is used in this specification to indicate
UDS
and
LDS
.