Motorola M68000 User Manual page 165

Num Characteristic
29 AS, DS Negated to Data-In Invalid
(Hold Time on Read)
29A AS, DS Negated to Data-In High
Impedance
30 AS, DS Negated to BERR
Negated
31 2 , 5 DTACK Asserted to Data-In Valid
(Setup Time)
32 HALT and RESET Input Transition
Time
33 Clock High to BG Asserted
34 Clock High to BG Negated
35 BR Asserted to BG Asserted
36 7
BR Negated to BG Negated
38 BG Asserted to Control, Address,
Data Bus High Impedance (AS
Negated)
39 BG Width Negated
44 AS, DS Negated to VPA Negated
47 5
Asynchronous Input Setup Time
48 2 , 3 BERR Asserted to DTACK
Asserted
53 Data-Out Hold from Clock High
55 R/ W Asserted to Data Bus
Impedance Change
56 4
HALT/RESET Pulse Width
58 7
BR Negated to AS, DS, R/ W
Driven
58A 7 BR Negated to FC, VMA Driven
NOTES:1. For a loading capacitance of less than or equal to 50 pF, subtract 5 ns from the value given in the
maximum columns.
2. Actual value depends on clock period.
3.I f #47 is satisfied for both DTACK and BERR , #48 may be ignored. In the absence of DTACK, BERR is an
asynchronous input using the asynchronous input setup time (#47).
4. For power-up, the MC68EC000 must be held in the reset state for 520 clocks to allow stabilization of on-
chip circuitry. After the system is powered up, #56 refers to the minimum pulse width required to
reset the processor.
5. If the asynchronous input setup time (#47) requirement is satisfied for DTACK, the DTACK -asserted to data
setup time (#31) requirement can be ignored. The data must only satisfy the data-in to clock low
setup time (#27) for the following clock cycle.
6. When AS and R/W are equally loaded ( 20;pc), subtract 5 ns from the values given in these columns.
7. The minimum value must be met to guarantee proper operation. If the maximum value is exceeded,
BG may be reasserted.
8. DS is used in this specification to indicate UDS and LDS .
MOTOROLA M68000 8-/16-/32-BIT MICROPROCESSORS USER'S MANUAL
Freescale Semiconductor, Inc.
8 MHz
Min Max Min
0 —
— 187
0 —
— 90
0 150
— 35
— 35
1.5 3.5 1.5
1.5 3.5 1.5
— 55
1.5 1.5
0 55
5 —
20 —
0 —
30 —
10 —
1.5 — 1.5
1 —
For More Information On This Product,
Go to: www.freescale.com
10 MHz 12.5 MHz
Max Min Max
0 — 0 —
— 150 — 120
0 — 0 —
— 65 — 50
0 150 0 150
— 35 — 35
— 35 — 35
3.5 1.5 3.5
3.5 1.5 3.5
— 55 — 55
1.5
0 55 0 55
5 — 5 —
20 — 20 —
0 — 0 —
20 — 10 —
10 — 10 —
— 1.5 —
1 — 1 —
16.67 MHz 20 MHz
Min Max Min Max
0 — 0 —
— 90 — 75
0 — 0 —
— 50 — 42
0 150 0 150
0 30 0 25
0 30 0 25
1.5 3.5 1.5 3.5
1.5 3.5 1.5 3.5
— 50 — 42
1.5 1.5 —
0 50 0 42
5 — 5 —
10 — 10 —
0 — 0 —
0 — 0 —
10 — 10 —
1.5 — 1.5 —
1 — 1 —
10-25
Unit
ns
ns
ns
ns
ns
ns
ns
Clks
Clks
ns
Clks
ns
ns
ns
ns
ns
Clks
Clks
Clks