Chapter 3: Tcl

R

♦padgroup—group definition on pad set

♦offset—offset in/out constraint

constraint_details specifies the details for the specified constraint type as follows:

♦maxdelay—timing in ns

♦period—time in ns and clock pad

♦padgroup—group name and pads to be included in group

♦offset—[timegroup] P2SC2P <clock_pad_name> <time_in_ns> [C2PP2S <clock_pad_name> <time_in_ns>] [<“data pad or pad group”>]

Note: There are two types of offset constraints: P2S, which is pad-to-synchronous (offset in constraint), and C2P, which is clock-to-pad (offset out constraint).

Example:

% timing_analysis set_constraint stopwatch_timing

 

period “13 sclk”

 

 

Description:

In this example, a period constraint is set for the stopwatch_timing

 

analysis. Note that the constraint details, “13 sclk”, are entered as a

 

text string.

Tcl Return:

1 if the constraint was set successfully, 0 otherwise.

set_endpoints (set source and destination endpoints)

The timing_analysis set_endpoints command sets source and destination endpoints for a path endpoints analysis.

%timing_analysis set_endpoints <analysis name> <qualifier> <category> <items>

timing_analysis is the name of the Xilinx Tcl command.

set_endpoints is the name of the timing_analysis subcommand.

analysis_name specifies the name of the analysis previously created with the timing_analysis new command.

qualifier specifies whether source (from) or destination (to) points are being set for custom analysis.

category specifies the resources type for the sources and destinations. These are family dependent.

items specifies the resource items to be put into path endpoint sources or destinations.

Example:

% timing_analysis set_endpoints stopwatch_timing from ffs *

 

 

Description:

In this example, the asterisk (*) was used as a wildcard to add all items

 

in the flip-flop category to the sources for the path endpoints analysis.

Tcl Return:

1 if the endpoints were set successfully, 0 otherwise.

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Development System Reference Guide

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Xilinx 8.2i manual Setendpoints set source and destination endpoints, Timinganalysis setconstraint stopwatchtiming
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8.2i specifications

Xilinx 8.2i is a significant version of the Xilinx ISE (Integrated Software Environment) that emerged in the early 2000s, marking an important milestone in the world of FPGA (Field-Programmable Gate Array) development. This version introduced a slew of advanced features, technologies, and characteristics that made it an indispensable tool for engineers and developers in designing, simulating, and implementing digital circuits.

One of the standout features of Xilinx 8.2i is its enhanced design entry capabilities. This version supports multiple design entry methods, including schematic entry, VHDL, and Verilog HDL, giving engineers the flexibility to choose their preferred approach. The integrated environment provides user-friendly graphical interfaces, making it accessible for both novice and experienced users.

Xilinx 8.2i's synthesis tools have been improved to enable more efficient design compilation and optimization. The new algorithms used in this version facilitate faster synthesis times while reducing power consumption and improving performance. Furthermore, it features support for advanced FPGA architectures, which allows for the implementation of more complex designs with greater efficiency.

The implementation tools in Xilinx 8.2i include advanced place and route capabilities, utilizing state-of-the-art algorithms for optimized resource usage. These tools enable designers to make better use of FPGA resources, ensuring that designs fit within the constraints of the target device while maximizing performance.

Another key characteristic of Xilinx 8.2i is its extensive support for various Xilinx devices such as the Spartan, Virtex, and CoolRunner series. This compatibility ensures that developers can leverage the powerful features of these FPGA families, including high-speed transceivers and DSP slices.

Xilinx 8.2i also places a strong emphasis on simulation and verification. The version integrates with various simulation tools, allowing for thorough testing of the designs before implementation. This reduces the risk of errors and ensures that the final product meets specifications.

In addition, this version includes support for design constraints, enabling engineers to specify timing, area, and other critical design parameters. By accommodating constraints, Xilinx 8.2i helps in achieving reliable and efficient designs tailored to project needs.

In summary, Xilinx 8.2i is a robust software development tool that enhances the design process for FPGAs. Its comprehensive features, including multiple design entry options, advanced synthesis and implementation tools, extensive device support, and strong simulation capabilities, make it a valuable resource for engineers and developers striving for innovation in digital design.
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