XC3000FM Datasheet, PDF (32/50 Pages) Xilinx, Inc – XC3000 Logic Cell Array Families

XC3000, XC3000A, XC3000L, XC3100, XC3100A Logic Cell Array Families
1.00
MAX ^{COMMERCIAL (4.75 V)}
0.80
SPECIFIED WORST-CASE VALUES
MAX ^{MILITARY (4.5 V)}
0.60
TYPICAL COMMERCIAL
(+ 5.0 V, 25°C)
TYPICAL MILITARY
0.40
MIN
MIN
CCOOMMMMEERRCCIIAALL
(4.75
(5.25
V)
V)
MIN ^{MILITARY (4.5 V)}
MIN ^{MILITARY (5.5 V)}
0.20
– 55
– 40
– 20
0
25
40
70 80
100
TEMPERATURE (°C)
Figure 26. Relative Delay as a Function of Temperature, Supply Voltage and Processing Variations
125
X6094
300
250
200
150
100
XC3100-3
50
XC3000-125
0
CLB Levels: 4 CLBs
Gate Levels: (4-16)
3 CLBs
(3-12)
2 CLBs
(2-8)
1 CLB
(1-4)
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Rate
X3250
Figure 27. Clock Rate as a Function of Logic Complexity
(Number of Combinational Levels between
Flip-Flops)
Power
Power Distribution
Power for the LCA device is distributed through a grid to
achieve high noise immunity and isolation between logic
and I/O. Inside the LCA device, a dedicated V_CC and
ground ring surrounding the logic array provides power to
the I/O drivers. An independent matrix of V_CC and
groundlines supplies the interior logic of the device. This
power distribution grid provides a stable supply and ground
for all internal logic, providing the external package power
pins are all connected and appropriately decoupled. Typi-
cally a 0.1-µF capacitor connected near the V_CC and
ground pins will provide adequate decoupling.
Output buffers capable of driving the specified 4- or 8-mA
loads under worst-case conditions may be capable of
driving as much as 25 to 30 times that current in a best
case. Noise can be reduced by minimizing external load
capacitance and reducing simultaneous output transitions
in the same direction. It may also be beneficial to locate
heavily loaded output buffers near the ground pads. The
I/O Block output buffers have a slew-limited mode which
should be used where output rise and fall times are not
speed critical. Slew-limited outputs maintain their dc drive
capability, but generate less external reflections and inter-
nal noise.
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