XCV405E-7BG556I XILINX [Xilinx, Inc], XCV405E-7BG556I Datasheet - Page 42

• Manufacturer Part Number: XCV405E-7BG556I
• Description: Virtex-E 1.8 V Extended Memory Field Programmable Gate Arrays
• Manufacturer: XILINX [Xilinx, Inc]

Virtex™-E 1.8 V Extended Memory Field Programmable Gate Arrays
Input termination techniques include the following:
•
•
These termination techniques can be applied in any combi-
nation. A generic example of each combination of termina-
tion methods appears in
Simultaneous Switching Guidelines
Ground bounce can occur with high-speed digital ICs when
multiple outputs change states simultaneously, causing
undesired transient behavior on an output, or in the internal
logic. This problem is also referred to as the Simultaneous
Switching Output (SSO) problem.
Ground bounce is primarily due to current changes in the
combined inductance of ground pins, bond wires, and
ground metallization. The IC internal ground level deviates
from the external system ground level for a short duration (a
few nanoseconds) after multiple outputs change state
simultaneously.
Ground bounce affects stable Low outputs and all inputs
because they interpret the incoming signal by comparing it
to the internal ground. If the ground bounce amplitude
exceeds the actual instantaneous noise margin, then a
non-changing input can be interpreted as a short pulse with
a polarity opposite to the ground bounce.
Table 21
of simultaneously switching outputs allowed per output
power/ground pair to avoid the effects of ground bounce.
Refer to
power/ground pairs for each Virtex-E device and package
combination.
Module 2 of 4
38
Figure 43: Overview of Standard Input and Output
None
Parallel (Shunt)
provides the guidelines for the maximum number
Unterminated Output Driving
Table 22
a Parallel Terminated Input
Series Terminated Output
Unterminated
Z=50
Z=50
Z=50
Termination Methods
V
V
REF
REF
for the number of effective output
V
TT
Figure
43.
Driving a Parallel Terminated Input
Series-Parallel Terminated Output
Series Terminated Output Driving
Double Parallel Terminated
a Parallel Terminated Input
V
V
TT
TT
Z=50
Z=50
Z=50
V
REF
V
V
REF
REF
V
TT
V
V
x133_07_111699
TT
TT
www.xilinx.com
1-800-255-7778
Table 21:
Table 22:
LVTTL Slow Slew Rate, 2 mA drive
LVTTL Slow Slew Rate, 4 mA drive
LVTTL Slow Slew Rate, 6 mA drive
LVTTL Slow Slew Rate, 8 mA drive
LVTTL Slow Slew Rate, 12 mA drive
LVTTL Slow Slew Rate, 16 mA drive
LVTTL Slow Slew Rate, 24 mA drive
LVTTL Fast Slew Rate, 2 mA drive
LVTTL Fast Slew Rate, 4 mA drive
LVTTL Fast Slew Rate, 6 mA drive
LVTTL Fast Slew Rate, 8 mA drive
LVTTL Fast Slew Rate, 12 mA drive
LVTTL Fast Slew Rate, 16 mA drive
LVTTL Fast Slew Rate, 24 mA drive
LVCMOS2
PCI
GTL
GTL+
HSTL Class I
HSTL Class III
HSTL Class IV
SSTL2 Class I
SSTL2 Class II
SSTL3 Class I
SSTL3 Class II
CTT
AGP
Note: This analysis assumes a 35 pF load for each output.
Pkg/Part
BG560
FG676
FG900
Guidelines for Maximum Number of
Simultaneously Switching Outputs per
Power/Ground Pair
Virtex-E Extended Memory Family
Equivalent Power/Ground Pairs
Standard
XCV405E
DS025-2 (v2.1) July 17, 2002
56
BGA, FGA
Package
XCV812E
68
41
29
22
17
14
40
24
17
13
10
10
18
15
10
11
14
9
8
5
8
4
4
9
5
7
9
56
R