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8XC196MD
EXPLANATION OF AC SYMBOLS
Each symbol is two pairs of letters prefixed by ‘‘T’’ for time. The characters in a pair indicate a signal and its
condition, respectively. Symbols represent the time between the two signal/condition points.
Conditions:
Signals:
H
D High
L
D Low
V
D Valid
X
D No Longer Valid
Z
D Floating
A
D Address
B
D BHE
C
D CLKOUT
D
D DATA
G D Buswidth
H
D HOLD
HA D HLDA
L
D ALE/ADV
BR D BREQ
R
D RD
W D WR/WRH/WRL
X
D XTAL1
Y
D READY
Q D Data Out
AC ELECTRICAL CHARACTERISTICS
(Over Specified Operating Conditions)
Test Conditions: Capacitive load on all pins
e
100 pF, Rise and fall times
e
10 ns, F
OSC
e
16 MHz.
The system must meet the following specifications to work with the 87C196MD:
Symbol
Parameter
Min
Max
Units
Notes
F
XTAL
Frequency on XTAL1
8
16
MHz
3
T
OSC
1/F
XTAL
62.5
125
ns
T
AVYV
Address Valid to READY Setup
2 T
OSC
b
75
T
OSC
b
70
ns
T
LLYV
ALE Low to READY Setup
ns
4
T
YLYH
Not READY Time
No Upper Limit
ns
T
CLYX
READY Hold after CLKOUT Low
0
T
OSC
b
30
2 T
OSC
b
40
2 T
OSC
b
75
T
OSC
b
60
ns
1
T
LLYX
READY Hold after ALE Low
T
OSC
b
15
ns
1
T
AVGV
Address Valid to BUSWIDTH Setup
ns
T
LLGV
ALE Low to BUSWIDTH Setup
ns
4
T
CLGX
Buswidth Hold after CLKOUT Low
0
ns
T
AVDV
Address Valid to Input Data Valid
3 T
OSC
b
55
T
OSC
b
22
T
OSC
b
50
ns
2
T
RLDV
RD Active to Input Data Valid
ns
2
T
CLDV
CLKOUT Low to Input Data Valid
ns
T
RHDZ
End of RD to Input Data Float
T
OSC
ns
T
RXDX
Data Hold after RD Inactive
0
ns
NOTES:
1. If Max is exceeded, additional wait states will occur.
2. If wait states are used, add 2 T
OSC
*
N, where N
e
number of wait states.
3. Testing performed at 8 MHz. However, the device is static by design and will typically operate below 1 Hz.
4. These timings are included for compatibility with older
b
90 and BH products. They should not be used for newer high-
speed designs.
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