MC68000 MOTOROLA [Motorola, Inc], MC68000 Datasheet - Page 313

• Manufacturer Part Number: MC68000
• Manufacturer: MOTOROLA [Motorola, Inc]

6.14 AC ELECTRICAL SPECIFICATIONS—CHIP-SELECT TIMING
MOTOROLA
IACK1,IACK6,
NOTES:
(OUTPUT)
(OUTPUT)
(OUTPUT)
(OUTPUT)
CS0–CS3
Num.
1.The minimum value must be met to guarantee write protection operation.
2.This specification is valid when the ADCE or WPVE bits in the SCR are set.
3.Also applies after a timeout of the hardware watchdog.
154
160
161
162
163
164
165
167
168
169
DTACK
IACK7
BERR
CLKO
EXTERNAL MASTER
Clock Low to DTACK Low (1-6 Wait States)
AS Low to CS Low
AS High to CS High
Address Valid to AS Low
R/W Valid to AS Low (see Note 1)
AS Negated to Address Hold Time
AS Low to DTACK Low (0 Wait State)
AS High to DTACK High
AS Low to BERR Low (see Note 2)
AS High to BERR High Impedance (see
Notes 2 and 3)
S0
Figure 6-14. Internal Master Chip-Select Timing Diagram
S1
Characteristic
S2
S3
156
153
150
S4
(see Figure 6-15)
MC68302 USER’S MANUAL
S5
151
155
S6
S7
t
t
t
t
Symbol
t
t
ASHDTKH
ASHBERH
t
t
ASLDTKL
ASLBERL
ASHCSH
RWVASL
t
CLDTKL
ASLCSL
t
AVASL
S0
ASHAI
157
152
158
S1
Min
16.67 MHz
15
15
—
—
—
—
—
—
—
S2
0
S3
Max
30
30
30
45
30
30
30
—
—
—
S4
Min
12
12
—
—
—
—
—
—
—
0
20 MHz
Sw
Electrical Characteristics
Max
154
25
25
25
40
25
25
25
—
—
—
Sw
S5
Min
10
10
—
—
—
—
—
—
—
25 MHz
0
S6
Max
20
20
20
30
20
20
20
—
—
—
S7
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
S0
6-25