LogiBlox Modules

LogiBLOX is a graphical interactive tool for creating high-level modules, such as counters, shift registers, and multiplexers. LogiBLOX includes both a library of generic modules and a set of tools for customizing them. For detailed information see the LogiBLOX Reference/User Guide.

The modules you create with LogiBLOX can be used in designs generated with schematic editors from Aldec, Viewlogic, Mentor Graphics, and Cadence.

Use LogiBLOX modules whenever you need a customized version of a standard function. In contrast, a standard ready-made counter has a previously defined set of functions. If you want to use a counter with specific capabilities, you need to have available a library of different counters, one of which contains the functions you need. However, with a LogiBLOX counter, you start with a generic template and tailor its functionality to your needs.

You can use LogiBLOX to design your modules. The Module Selector is a graphical user interface. Use it to tailor modules to your requirements. This is the most common way to design modules in LogiBLOX.

Program Inputs and Outputs

The Module Selector is the LogiBLOX graphical user interface that you use to create a LogiBLOX module. Specifying a LogiBLOX module consists of a) selecting or deselecting optional pins on the symbol, and b) specifying various module attributes. The result is a module customized for a specific function.

After you complete the module specification, LogiBLOX uses its symbol generator, model generator, and netlist generator to create the following three outputs and store them in the current project directory:

• A schematic symbol for inclusion on the schematic
  
  The symbol generator creates a symbol definition file that your third-party interface converts into a schematic symbol.
  
  
• A behavioral VHDL simulation model
  
  The model generator creates a behavioral VHDL simulation model for the LogiBLOX module.
  
  The behavioral model permits the design to be simulated immediately in those environments that support mixed schematic and behavioral simulation.
  
  
• Verilog and EDIF gate-level netlists, produced as an alternative simulation medium
  
  

The netlist generator creates a gate-level netlist for the LogiBLOX module that is converted to the third-party's simulation format. These netlists permit immediate simulation of the design in gate-level simulation environments.

Schematic Design Flow

To use the program in a schematic-based environment, follow these steps:

1. Invoke the Module Selector from within your design entry tool.
   
   
2. Configure your project directory using the LogiBLOX Setup window.
   
   
3. Select a base module type (for example, Counter, Memory, or Shift-register)
   
   
4. Customize the module by selecting pins and specifying attributes.
   
   
5. After completely specifying a module, click on the OK button. Selecting OK initiates the generation of a schematic symbol and a simulation model for the selected module.
   
   
6. Place the module on your schematic.
   
   
7. Connect the LogiBLOX module to the other components on your schematic using ordinary nets, buses, or both.
   
   
8. Functionally simulate your design at any time.
   
   
9. Implement your design with the Xilinx implementation tools.
   
   
10. To simulate your design post-layout, convert your design to a timing netlist and use the back-annotation flow appropriate to your CAE tools.
    
    

Changing a Schematic Module

To change a module that you have already placed on your schematic, select the module and invoke the Module Selector. The Module Selector displays the settings of the module that you want to edit.