10-28 M68000 8-/16-/32-BIT MICROPROCESSORS USER'S MANUAL MOTOROLA
10.15 MC68EC000 AC ELECTRICAL SPECIFICATIONS—BUS
ARBITRATION
(VCC=5.0VDC ± 5%; GND=0 VDC; T
A
= T
L
TO T
H
; see Figure 10-14)
Num Characteristic 8 MHz 10 MHz 12.5 MHz 16.67 MHz 20 MHz Unit
Min Max Min Max Min Max Min Max Min Max
7 Clock High to Address, Data
Bus High Impedance
(Maximum)
— 55 — 55 — 55 — 50 — 42 ns
16 Clock High to Control Bus High
Impedance
— 55 — 55 — 55 — 50 — 42 ns
33 Clock High to BG Asserted — 35 — 35 — 35 0 30 0 25 ns
34 Clock High to BG Negated — 35 — 35 — 35 0 30 0 25 ns
35 BR Asserted to BG Asserted 1.5 3.5 1.5 3.5 1.5 3.5 1.5 3.5 1.5 3.5 Clks
36
7
BR Negated to BG Negated 1.5 3.5 1.5 3.5 1.5 3.5 1.5 3.5 1.5 3.5 Clks
38 BG Asserted to Control,
Address, Data Bus High
Impedance (AS Negated)
— 55 — 55 — 55 — 50 — 42 ns
39 BG Width Negated 1.5 — 1.5 — 1.5 — 1.5 — 1.5 — Clks
47 Asynchronous Input Setup
Time
5—5—5—5—5—ns
58
1
BR Negated to AS , DS, R/W
Driven
1.5 — 1.5 — 1.5 — 1.5 — 1.5 — Clks
58A
1
BR Negated to FC Driven 1 — 1 — 1 — 1 — 1 — Clks
NOTES: 1.The minimum value must be met to guarantee proper operation. If the maximum value is exceeded, BG may
be reasserted.
2.DS is used in this specification to indicate UDS and LDS.
Frees
cale Semiconductor,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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