Motorola MC68020 User Manual page 284

AC ELECTRICAL CHARACTERISTICS—READ AND WRITE CYCLES
(Continued)
Num. Characteristics
29 AS, DS Negated to Data-In Invalid
(Data-In Hold Time)
29A AS, DS Negated to Data-In
(High Impedance)
30 Clock Low to Data-In Invalid
(Data-In Hold Time)
2
31 DSACK≈ Asserted to Data-In Valid
3
31A DSACK≈ Asserted to DSACK≈ Valid
(DSACK≈ Asserted Skew)
32 RESET Input Transition Time
33 Clock Low to BG Asserted
34 Clock Low to BG Negated
35 BR Asserted to BG Asserted (RMC Not
Asserted)
*
37 BGACK Asserted to BG Negated
6
*
37A BGACK Asserted to BR Negated
39 BG Width Negated
39A BG Width Asserted
*
40 Clock High to DBEN Asserted (Read)
*
41 Clock Low to DBEN Negated (Read)
*
42 Clock Low to DBEN Asserted (Write)
*
43 Clock High to DBEN Negated (Write)
*
44 R/ W Low to DBEN Asserted (Write)
5
*
45 DBEN Width Asserted
46 R/ W Width Valid (Write or Read)
47A Asynchronous Input Setup Time
47B Asynchronous Input Hold Time
4
48 DSACK≈ Asserted to BERR, HALT Asserted
53 Data-Out Hold from Clock High
55 R/ W Valid to Data Bus Impedance Change
56 RESET Pulse Width (Reset Instruction)
57 BERR Negated to HALT Negated (Rerun)
10
*
58
BGACK Negated to Bus Driven
10
59 BG Negated to Bus Driven
*
This specification does not apply to the MC68EC020.
**
These specifications represent an improvement over previously published specifications for the 25-MHz MC68020
and are valid only for product bearing date codes of 8827 and later.
MOTOROLA
16.67 MHz
Min Max
0 —
— 60
15 —
— 50
— 15
— 1.5
0 30
0 30
1.5 3.5
1.5 3.5
0 1.5
90 —
90 —
0 30
0 30
0 30
0 30
15 —
Read 60 —
Write 120 —
150 —
5 —
15 —
— 30
0 —
30 —
512 —
0 —
1 —
1 —
M68020 USER'S MANUAL
**
20 MHz 25 MHz
Min Max Min Max
0 — 0 —
— 50 — 40
15 — 10 —
— 43 — 32
— 10 — 10
— 1.5 — 1.5
0 25 0 20
0 25 0 20
1.5 3.5 1.5 3.5
1.5 3.5 1.5 3.5
0 1.5 0 1.5
75 — 60 —
75 — 60 —
0 25 0 20
0 25 0 20
0 25 0 20
0 25 0 20
10 — 10 —
50 — 40 —
100 — 80 —
125 — 100 —
5 — 5 —
15 — 10 —
— 20 — 18
0 — 0 —
25 — 20 —
512 — 512 —
0 — 0 —
1 — 1 —
1 — 1 —
33.33 MHz
Min Max Unit
0 — ns
— 30 ns
10 — ns
— 17 ns
— 10 ns
— 1.5 Clks
0 20 ns
0 20 ns
1.5 3.5 Clks
1.5 3.5 Clks
0 1.5 Clks
50 — ns
50 — ns
0 15 ns
0 15 ns
0 15 ns
0 15 ns
5 — ns
30 — ns
60 —
75 — ns
5 — ns
10 — ns
— 15 ns
0 — ns
20 — ns
512 — Clks
0 — ns
1 — Clks
1 — Clks
10-9