National Instruments HPC467064 Computer Hardware User Manual


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30 MHz
AC Electrical Characteristics
(Continued)
(See Notes 1 and 4 and
Figures 1
thru
5
) V
CC
e
5V
g
10% T
A
e
0
Cto
a
70
C for HPC467064 (Continued)
Symbol and Formula Parameter Min Max Units Notes
t
ARR
e
 t
C
b
5 ALE Falling Edge to RD Falling Edge 12 ns
t
ACC
e
t
C
a
WS
b
32 Data Input Valid after Address Output Valid 100 ns
t
RD
e
 t
C
a
WS
b
39 Data Input Valid after RD Falling Edge 60 ns
t
RW
e
 t
C
a
WS
b
14 RD Pulse Width 85 ns
t
DR
e
 t
C
b
15 Hold of Data Input Valid after RD Rising Edge 0 35 ns
t
RDA
e
t
C
b
15 Bus Enable after RD Rising Edge 51 ns
t
ARW
e
 t
C
b
5 ALE Falling Edge to WR Falling Edge 28 ns
t
WW
e
 t
C
a
WS
b
15 WR Pulse Width 101 ns
t
V
e
 t
C
a
WS
b
5 Data Output Valid before WR Rising Edge 94 ns
t
HW
e
 t
C
b
10 Hold of Data Valid after WR Rising Edge 7 ns
t
DAR
e
 t
C
a
WS
b
50 Falling Edge of ALE to Falling Edge of RDY 33 ns
t
RWR
e
t
C
RDY Pulse Width 66 ns
Read CyclesWrite Cycles
Ready
Input
This maximum frequencyis attainable provided that thisexternal baud clock hasa duty cycle such thatthe high period includestwo (2) falling edges ofthe CK2
clock
Note C
L
e
40 pF
Note 1 These AC Characteristicsare guaranteed with external clock drive onCKI having 50% duty cycle and withless than 15 pF load on CKOwith rise and fall
times (t
CKIR
and t
CKIL
) on CKI input less than 25 ns
Note 2 Donot design withthis parameter unlessCKI is drivenwith an active signalWhen using apassive crystal circuitits stability isnot guaranteed if eitherCKI
or CKO is connected to any external logic other than the passive components of the crystal circuit
Note 3t
HAE
is spec’dfor casewith HLD fallingedge occurringat thelatest timecan be acceptedduring thepresent CPUcycle beingexecuted If HLDfalling edge
occurs later t
HAE
may be as long as (3t
C
a
4WS
a
72t
C
a
100) depending on the following CPU instruction cycles its wait states and ready input
Note 4WS
e
t
WAIT
c
(number ofpre-programmed wait states)Minimum andmaximum values arecalculated atmaximum operating frequencyt
c
e
3000 MHz
with one wait state programmed
Note 5 Due to emulation restrictionsactual limits will be better
Note 6 Due to tester limitationsactual limits will be better
CKI Input Signal Characteristics
RiseFall Time
TLDD11046–2
Duty Cycle
TLDD11046–3
FIGURE 1 CKI Input Signal
6
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