DS031 Datasheet, PDF (18/318 Pages) Xilinx, Inc – Summary of Features

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Virtex-II Platform FPGAs: Functional Description
Figure 12 provides examples illustrating the use of the SSTL2_I_DCI, SSTL2_II_DCI, SSTL3_I_DCI, and SSTL3_II_DCI I/O
standards. For a complete list, see the Virtex-II Platform FPGA User Guide.
SSTL2_I
SSTL2_II
SSTL3_I
SSTL3_II
Conventional
V_CCO/2
R
Z0
R/2
VCCO/2 VCCO/2
R
R
Z0
R/2
V_CCO/2
R
Z0
R/2
VCCO/2 VCCO/2
R
R
Z0
R/2
DCI Transmit
Conventional
Receive
25Ω⁽¹⁾
Virtex-II DCI
V_CCO/2
R
Z0
VCCO
25Ω⁽¹⁾
2R
2R
Virtex-II DCI
VCCO/2
R
Z0
25Ω⁽¹⁾
Virtex-II DCI
VCCO/2
R
Z0
VCCO
25Ω⁽¹⁾ _2R
2R
Virtex-II DCI
VCCO/2
R
Z0
Conventional
Transmit
DCI Receive
VCCO
2R
Z0
R/2
2R
Virtex-II DCI
VCCO/2
R
Z0
R/2
VCCO
2R
2R
Virtex-II DCI
VCCO
2R
Z0
R/2
2R
Virtex-II DCI
VCCO/2
R
Z0
R/2
VCCO
2R
2R
Virtex-II DCI
DCI Transmit
DCI Receive
25Ω⁽¹⁾
Virtex-II DCI
VCCO
2R
VCCO
25Ω⁽¹⁾
2R
VCCO
2R
25Ω⁽¹⁾
Z0
Z0
2R
2R
Virtex-II DCI Virtex-II DCI
2R
Virtex-II DCI
Virtex-II DCI
VCCO
2R
Z0
2R
VCCO
25Ω⁽¹⁾ _2R
VCCO
2R
Z0
2R
2R
Virtex-II DCI Virtex-II DCI
Virtex-II DCI
Bidirectional
Reference
Resistor
N/A
VRN = VRP = R = Z0
VCCO
25Ω⁽¹⁾
2R
VCCO
2R
Z0
2R
2R _25Ω(1)
Virtex-II DCI
Virtex-II DCI
VRN = VRP = R = Z0
N/A
VCCO
25Ω⁽¹⁾
2R
VCCO
2R
Z0
2R
2R _25Ω(1)
Virtex-II DCI
Virtex-II DCI
VRN = VRP = R = Z0
VRN = VRP = R = Z0
Recommended
Z0⁽²⁾
50 Ω
50 Ω
50 Ω
50 Ω
Notes:
1. The SSTL-compatible 25Ω series resistor is accounted for in the DCI buffer, and it is not DCI controlled.
2. Z0 is the recommended PCB trace impedance.
DS031_65b_112502
Figure 12: SSTL DCI Usage Examples
DS031-2 (v3.5) November 5, 2007
Product Specification
www.xilinx.com
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