Xilinx virtex-5 fpga User Manual

Virtex-5 FPGA User Guide www.xilinx.com 241
UG190 (v5.0) June 19, 2009
Specific Guidelines for I/O Supported Standards
Table 6-5 details the allowed attributes that can be applied to the LVTTL I/O standard.
LVCMOS (Low Voltage Complementary Metal Oxide Semiconductor)
LVCMOS is a widely used switching standard implemented in CMOS transistors. This
standard is defined by JEDEC (JESD 8-5). The LVCMOS standards supported in Virtex-5
FPGAs are: LVCMOS12, LVCMOS15, LVCMOS18, LVCMOS25, and LVCMOS33.
Sample circuits illustrating both unidirectional and bidirectional LVCMOS termination
techniques are shown in Figure 6-29 and Figure 6-30.
Table 6-5: Allowed Attributes for the LVTTL I/O Standard
Attributes
Primitives
IBUF/IBUFG OBUF/OBUFT IOBUF
IOSTANDARD LVTTL LVTTL LVTTL
DRIVE UNUSED 2, 4, 6, 8, 12, 16, 24 2, 4, 6, 8, 12, 16, 24
SLEW UNUSED {FAST, SLOW} {FAST, SLOW}
X-Ref Target - Figure 6-29
Figure 6-29: LVCMOS Unidirectional Termination
Z
0
IOB
IOB
LVCMOS
LVCMOS
Z
0
IOB
IOB
LVCMOS
LVCMOS
Z
0
IOB
IOB
LVCMOS
LVCMOS
ug190_6_26_022806
V
TT
Note: V
TT
is any voltage from 0V to V
CCO
R
P
= Z
0
R
S
= Z
0
– R
D

Xilinx virtex-5 fpga Specifications

General

Brand	Xilinx
Model	virtex-5 fpga
Category	Computer Hardware
Language	English