Virtex-II 1.5V Field-Programmable Gate Arrays
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DS031-2 (v1.5) April 2, 2001 www.xilinx.com Module 2 of 4
Advance Product Specification 1-800-255-7778 33
The Xilinx Foundation ISE product family includes synthesis
capabilities from both FPGA Express and a proprietar y syn-
thesis tool referred to as Xilinx Synthes is Tec hnology. Having
two seamlessly integrated synthesis engines within the Foun-
dation ISE products provides an alternative set of optimization
techniques for designs, helping to ensure that Foundation ISE
can meet even the toughest timing requirements.
Both FPGA Express and Xilinx Synthesis Technology sup-
port the synthesis of VHDL and Verilog; however, only
FPGA Express enables mixed-language synthesis. Future
releases of the ISE design environment are planned to also
integrate other third party synthesis tools, like Synplicity
Synpli fy and Exemplar's Leon ar do Spe ct rum.
Design Implementati on
The Alliance Series and Foundation Series development
systems both include Xilinx timing-driven implementation
tools, frequently called “place and route” software. This
robust suite of tools enables the creation of an intuitive, fle x-
ible, tightly integrated design flow that efficiently bridges the
“logical” and “physical” design domains. This simplifies the
task of defining a design, including its behavior, timing
requirements, and optional la y out (or floorplanning), as well
as simplifying the task of analyzing repor ts generated dur-
ing the implementation process.
The Vir tex-II implementation process is comprised of Syn-
thesis, translation, mapping, place and route, and configu-
ration file generation. While the tools can be run individually,
many designers choose to run the entire implementation
process with the click of a button. To assist those who prefer
to script their design flows, Xilinx provides Xflow, an auto-
mated single command line process.
Design Verification
In addition to conventional design verification using static
timing analysis or dynamic timing analysis (simulation),
powerful in-circuit debuggin g techniques using Xilinx Chip-
Scope ILA (Integrated Logic Analy sis) is available. In these
reconfigurable Xilinx FPGAs, designs can be v erified in real
time without the need for extensive sets of software simula-
tion vectors. The development system supports both soft-
ware simulation and in-circuit debugging techniques.
For simulati on, the sys tem extracts post-l ayout timing infor-
mation from the design database, and back-annotates this
information into the netlist for use by the simulator . The back
annotat ion features a vari ety of patente d Xilinx tech niques,
resulting in the industry’s most powerful simulation flows.
Alterna tively, the use r ca n veri fy tim ing - critic al po rtions of a
design using the TRCE® static timing analyzer, or using a
third party static timing analysis tool by exporting timing
data in the STAMP data format.
For in- circuit debuggin g, ChipS cope IL A enables desi gners
to analyze the real-time behavior of a de vice while operating
at full system speeds. Logic analysis commands and cap-
tured data are transf erred between the ChipScope software
and ILA cores within the Virtex-II FPGA, using industry
standard JTAG protocols. These JTAG transactions are
driven over an optional download cable (MultiLINX or
JTAG), c onnec ting th e Virtex device in t he tar get sy stem t o
a PC or workstation.
ChipScope ILA was designed to look and feel like a logic
analyzer , making it easy to begin debugging a design imme-
diately. Modifications to the desired logic analysis can be
downloaded into the system in a matter of minutes.
Other Unique Features of Virtex-II Design
Flow
Xilinx design flows feature a number of unique capabil ities.
Among thes e are efficien t in crementa l HDL des ign fl ows; a
robust capability that is enabled by Xilinx exclusive hierar-
chical floorplanning capabilities. Another powerful design
capability only available in the Xilinx design flow is “Modular
Design”, part of the X ilinx su ite of team design tools, which
enables autonomous design, implementation, and verifica-
tion of design modules.
Incremental Synthesis
Xilinx unique hierarchical floorplanning capabilities enable
designers to create a programmable logic design by isolating
design changes within one hierarchical “logic block”, and
perform synthesis, verification and implementation pro-
cesses on that specific logic bloc k. By preserving the logic in
unchanged portions of a design, Xilinx incremental design
makes the high-density design process more efficient.
Xilinx hierarchical floorplanning capabilities can be speci-
fied using the high-level floorplanner or a preferred RTL
floorplanner (see the Xilinx web site for a list of suppor ted
EDA partners). When used in conjunction with one of the
EDA partners’ floorplanners, higher performance results
can be achieved, as many synthesis tools use this more
predic table detaile d physical im plementation i nformat ion to
establish more aggressive and accurate timing estimates
when performing their logic optimizations.
Modular Design
Xilinx in novative modular des ig n c apa bil iti es take the in cr e-
mental design process one step further by enabling the
designer to delegate responsibility for completing the
design, synthesis, verification, and implementation of a hier-
archical “logic block” to an arbitrary number of designers -
assigning a specific region within the target FPGA for e xclu-
sive use by each of the team members.
This team design capability enables an autonomous
approach to design modules, changing the hand-off point to
the lead designer or integrator from “my module works in
simulation” to “my module works in the FPGA”. This unique
design methodology also leverages the Xilinx hierarchical
floorplanning capabilities and enables the Xilinx (or EDA
partner) floorplanner to manage the efficient implementa-
tion of very high-density FPGAs.