0
R
Virtex-II 1.5V
Field-Programmable Gate Arrays
0
0
DS031-2 (v1.3) January 25, 2001
Advance Product Specification
Detailed Description
Input/Output Blocks (IOBs)
Virtex-II I/O blocks (IOBs) are provided in groups of two or four on the perimeter of each device.
Each IOB can be used as input and/or output for single-ended I/Os. Two IOBs can be used as a
differential pair. A differential pair is always connected to the same switch matrix, as shown in
Figure 1.
IOB blocks are designed for high performances I/Os, supporting 19 single-ended standards, as well
as differential signaling with LVDS, LDT, Bus LVDS, and LVPECL.
IOB
PAD4
Differential Pair
IOB
PAD3
Switch
Matrix
IOB
PAD2
Differential Pair
IOB
PAD1
DS031_30_101600
Figure 1: Virtex-II Input/Output Tile
Supported I/O Standards
Virtex-II IOB blocks feature SelectI/O inputs and outputs that support a wide variety of I/O signaling
standards. In addition to the internal supply voltage (VCCINT = 1.5V), output driver supply voltage
(VCCO) is dependent on the I/O standard (see Table 1). An auxiliary supply voltage
(VCCAUX = 3.3 V) is required, regardless of the I/O standard used. For exact supply voltage
absolute maximum ratings, DC Input and Output Levels.
Table 1: Supported Single-Ended I/O Standards
Board
Termination
Voltage (VTT
I/O
Standard
Output
VCCO
Input
VCCO
Input
VREF
)
LVTTL
3.3
3.3
2.5
1.8
1.5
3.3
3.3
2.5
1.8
1.5
N/A
N/A
N/A
N/A
N/A
N/A
LVCMOS33
LVCMOS25
LVCMOS18
LVCMOS15
N/A
N/A
N/A
N/A
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All other trademarks and registered trademarks are the property of their respective owners. All specifications are subject to change without notice.
DS031-2 (v1.3) January 25, 2001
Advance Product Specification
www.xilinx.com
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