Motorola MC68020 User Manual

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

General

Brand	Motorola
Model	MC68020
Category	Computer Hardware
Language	English