Xilinx ML505 User Manual

18 www.xilinx.com ML505/ML506/ML507 Evaluation Platform
UG347 (v3.1.1) October 7, 2009
Chapter 1: ML505/ML506/ML507 Evaluation Platform
R
Digitally Controlled Impedance
Some FPGA banks can support the digitally controlled impedance (DCI) feature in
Virtex-5 FPGAs. Support for DCI is summarized in Table 1-2.
2. DDR2 SODIMM
The ML50x platform is shipped with a single-rank unregistered 256 MB SODIMM. The
DDR2 SODIMM used is generally a Micron MT4HTF3264HY-53E or similar module. Serial
Presence Detect (SPD) using an IIC interface to the DDR DIMM is also supported with the
FPGA.
Note:
The board is only tested for DDR2 SDRAM operation at a 400 MHz data rate. Faster data
rates might be possible but are not tested.
MIG Compliance
The ML50x DDR2 interface is MIG pinout compliant. The MIG DDR2 routing guidelines
outlined in the Xilinx Memory Interface Generator (MIG) User Guide [Ref 17] have been
achieved.
The board’s DDR2 SODIMM memory interface is designed to the requirements defined by
the MIG User Guide using the MIG tool. The MIG documentation requires that designers
follow the MIG pinout and layout guidelines. The MIG tool generates and ensures that the
proper FPGA I/O pin selections are made in support of the board’s DDR2 interface. The
initial pin selection for the board was modified and then re-verified to meet the MIG
pinout requirements. To ensure a robust interface, the ML50x DDR2 layout incorporates
matched trace lengths for data signals to the corresponding data strobe signal as defined in
the MIG user guide. See Appendix C, “References” for links to additional information
about MIG and Virtex-5 FPGAs in general.
Table 1-2: DCI Capability of FPGA Bank
FPGA Bank DCI Capability
1 Not supported
2 Not supported
3 Not supported
4 Not supported
11 Yes, 49.9Ω resistors are installed
12 Not supported
13 Yes, 49.9Ω resistors are installed
14 Yes, 49.9Ω resistors are installed
15 Yes, 49.9Ω resistors are installed
16 Yes, 49.9Ω resistors are installed
17 Yes, 49.9Ω resistors are installed
18 Not supported
21 Yes, 49.9Ω resistors are installed
Downloaded from Elcodis.com electronic components distributor

Xilinx ML505 Specifications

General

Brand	Xilinx
Model	ML505
Category	Motherboard
Language	English