Electrical Characteristics
6-6
MC68302 USER’S MANUAL
MOTOROLA
6.8 AC ELECTRICAL SPECIFICATIONS—IMP BUS MASTER CYCLES
(see Figure 6-2, Figure 6-3, Figure 6-4, and Figure 6-5))
16.67 MHz
20 MHz
25 MHz
Num.
Characteristic
Symbol
Min
Max
Min
Max
Min
Max
Unit
6
Clock High to FC, Address Valid
t
CHFCADV
0
45
0
40
0
30
ns
7
Clock High to Address, Data Bus High Im-
pedance (Maximum)
Clock High to Address, FC Invalid (Mini-
mum)
t
CHADZ
—
50
—
42
—
33
ns
8
t
CHAFI
0
—
0
—
0
—
ns
9
Clock High to AS, DS Asserted (see Note 1)
t
CHSL
3
30
3
25
3
20
ns
11
Address, FC Valid to AS, DS Asserted
(Read) AS Asserted Write (see Note 2)
t
AFCVSL
15
—
12
—
10
—
ns
12
Clock Low to AS, DS Negated (see Note 1)
t
CLSH
—
30
—
25
—
20
ns
13
AS, DS Negated to Address, FC Invalid (see
Note 2)
AS (and DS Read) Width Asserted (see
Note 2)
t
SHAFI
15
—
12
—
10
—
ns
14
t
SL
120
—
100
—
80
—
ns
14A
DS Width Asserted, Write (see Note 2)
t
DSL
t
SH
t
CHCZ
t
SHRH
t
CHRH
t
CHRL
60
—
50
—
40
—
ns
15
AS, DS Width Negated (see Note 2)
60
—
50
—
40
—
ns
16
Clock High to Control Bus High Impedance
—
50
—
42
—
33
ns
17
AS, DS Negated to R/W Invalid (see Note 2)
15
—
12
—
10
—
ns
18
Clock High to R/W High (see Note 1)
—
30
—
25
—
20
ns
20
Clock High to R/W Low (see Note 1)
—
30
—
25
—
20
ns
20A
AS Asserted to R/W Low (Write) (see Notes
2 and 6)
Address FC Valid to R/W Low (Write) (see
Note 2)
R/W Low to DS Asserted (Write) (see Note
2)
t
ASRV
—
10
—
10
—
7
ns
21
t
AFCVRL
15
—
12
—
10
—
ns
22
t
RLSL
30
—
25
—
20
—
ns
23
Clock Low to Data-Out Valid
t
CLDO
—
30
—
25
—
20
ns
25
AS, DS, Negated to Data-Out Invalid (Write)
(see Note 2)
Data-Out Valid to DS Asserted (Write) (see
Note 2)
Data-In Valid to Clock Low (Setup Time on
Read) (see Note 5)
AS, DS Negated to DTACK Negated (Asyn-
chronous Hold) (see Note 2)
AS, DS Negated to Data-In Invalid (Hold
Time on Read)
t
SHDOI
15
—
12
—
10
—
ns
26
t
DOSL
15
—
12
—
10
—
ns
27
t
DICL
7
—
6
—
5
—
ns
28
t
SHDAH
0
110
0
95
0
75
ns
29
t
SHDII
0
—
0
—
0
—
ns
30
AS, DS Negated to BERR Negated
t
SHBEH
0
—
0
—
0
—
ns
31
DTACK Asserted to Data-In Valid (Setup
Time) (see Notes 2 and 5)
t
DALDI
—
50
—
42
—
33
ns
32
HALT and RESET Input Transition Time
t
RHr
, t
RHf
t
CHGL
t
CHGH
t
BRLGL
t
BRHGH
—
150
—
150
—
150
ns
33
Clock High to BG Asserted
—
30
—
25
—
20
ns
34
Clock High to BG Negated
—
30
—
25
—
20
ns
35
BR Asserted to BG Asserted (see Note 11)
2.5
4.5
2.5
4.5
2.5
4.5
clks
36
BR Negated to BG Negated (see Note 7)
1.5
2.5
1.5
2.5
1.5
2.5
clks