CPLDfit Options

CPLDfit Options

CPLDfit uses the following option files:

–blkfanin (Specify Maximum Fanin for Function Blocks)

-blkfanin[limit:4,40]

The -blkfanin option specifies the maximum number of function block inputs to use when fitting a device. If the value is near the maximum, this option reduces the possibility that design revisions will be able to fit without changing the pin-out. The maximum values vary with each supported CPLD architecture as shown below (default in parentheses):

CoolRunner XPLA3 = 40 (38)

CoolRunner-II = 40 (36)

–exhaust (Enable Exhaustive Fitting)

The values for inputs and pterms have an impact on design fitting. Occasionally different values must be tried before a design is optimally fit. The -exhaust option automates this process by iterating through all combinations of input and pterm limits until a fit is found. This process can take several hours depending on the size of the design. This option is off by default.

–ignoredatagate (Ignore DATA_GATE Attributes)

This option directs CPLDfit to ignore the DATA_GATE attribute when fitting a

CoolRunner-II device. This option is off by default.

Architecture Support: CoolRunner-II

–ignoretspec (Ignore Timing Specifications)

CPLDfit optimizes paths to meet timing constraints. The -ignoretspec option directs

CPLDfit to not perform this prioritized optimization. This option is off by default.

–init (Set Power Up Value)

-init [lowhighfpga]

The -init option specifies the default power up state of all registers. This option is overridden if an INIT attribute is explicitly placed on a register. Low and high are self- explanatory. The FPGA setting causes all registers with an asynchronous reset to power up low, all registers with an asynchronous preset to power up high, and remaining registers to power up low. The default setting is low.

Development System Reference Guide

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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.

Xilinx 8.2i manual CPLDfit Options

Models: 8.2i