Electrical Characteristics
MOTOROLA
MC68307 USER’S MANUAL
11-5
11.7 AC ELECTRICAL SPECIFICATIONS—READ AND WRITE CYCLES
Figure 11-2. Clock Timing
Num
Characteristic
3.3V
3.3 V or 5 V
Unit
8.33 MHz
16.67 MHz
Min
Max
Min
Max
6
Clock low to address valid
—
60
—
30
ns
7
Clock high to address, data bus high impedance (maximum)
—
100
—
50
ns
8
Clock high to address invalid (minimum)
0—0—
ns
91
Clock high to AS, CSx, LDS, UDS asserted
3
60
3
30
ns
112
Address valid to AS, CSx, LDS, UDS asserted (read)/AS, CSx asserted
(write)
30—15—
ns
121
Clock low to AS, CSx, LDS, UDS negated
3
60
3
30
ns
132
AS, CSx, LDS, UDS negated to address invalid
30
—
15
—
ns
142
AS, CSx, (and LDS, UDS read) width asserted
240
—
120
—
ns
14A2
LDS, UDS width asserted (write)
120
—
60
—
ns
152
AS, CSx, LDS, UDS width negated
120
—
60
—
ns
16
Clock high to control bus high impedence
—
100
—
50
ns
172
AS, CSx, LDS, UDS negated to R/W invalid
30
—
15
—
ns
181
Clock high to R/W high (read)
0
60
0
30
ns
201
Clock high to R/W low (write)
0
60
0
30
ns
20A2,3
AS, CSx, asserted to R/W low (write)
—
20
—
10
ns
212
Address valid to R/W low (write)
0—0—
ns
222
R/W low to LDS, UDS asserted (write)
60
—
30
—
ns
23
Clock low to data-out valid (write)
—
60
—
30
ns
252
AS, CSx, LDS, UDS negated to data-out invalid (write)
30
—
15
—
ns
262
Data-out valid to LDS,UDS asserted (write)
30
—
15
—
ns
274
Data-in valid to clock low (setup time on read)
10
—
5
—
ns
282
AS, CSx, LDS, UDS negated to DTACK negated (asynchronous hold)
0
220
0
110
ns
29
AS, CSx, LDS, UDS negated to data-in invalid (hold time on read)
0—0—
ns
29A
AS, CSx, LDS, UDS negated to data-in high impedance
—
180
—
90
ns
312,4
DTACK asserted to data-in valid (setup time)
—
100
—
50
ns
32
HALT,RESET and RSTIN input transition time
0
300
0
150
ns
33
Clock high to BG asserted
0
40
0
20
ns
0.8 V
3.8 V
Timing measurements are referenced to and from a low voltage of 0.8 V and a high
voltage of 3.8 V, unless otherwise noted. The voltage swing through this range
should start outside and pass through the range such that the rise or fall will be linear
between 0.8 V and 3.8 V.
NOTE:
4
5
1
2
3