This website uses cookies. By using this site, you consent to the use of cookies. For more information, please take a look at our Privacy Policy.
Home > FPGA Technical Tutorials > Design Recipes for FPGAs Using Verilog and VHDL > Mixed Signal Modeling > Mixed Domain Modeling

TABLE OF CONTENTS

Xilinx FPGA FPGA Forum

Mixed Domain Modeling

FONT SIZE : AAA

In order to use standard models, there has to be a framework for terminals and variables, which is where the standard packages are used. There is a complete IEEE Std (1076.1.1) that defines the standard packages in their entirety; however, it is useful to look at a simplified package (electrical systems in this case) to see how the package is put together.

For example electrical systems models need to be able to handle several key aspects: 

• electrical connection points; 

• electrical through variables, that is, current; 

• electrical across variables, that is, voltages.

The electrical systems package needs to encompass these elements. 

First the basic subtypes need to be defined. In all the analog systems and types, the basic underlying VHDL type is always real and so the voltage and current must be defined as subtypes of real.

1 subtype voltage is real;

2 subtype current is real;

Notice that there is no automatic unit assignment for either, but this is handled separately by the unit and symbol attributes in IEEE Std 1076.1.1. For example, for voltage the unit is defined as Volt and the symbol is defined as V.

The remainder of the basic electrical type definition then links these subtypes to the through and across variable of the type, respectively:

1 package electrical_system is

2 subtype voltage is real;

3 subtype current is real;

4 nature electrical is

5 voltage across

6 current through

7 ground reference;

8 end package electrical_system;


  • XC3090A-7PG175I

    Manufacturer:Xilinx

  • FPGA XC3000 Family 6K Gates 320 Cells 113MHz 5V 175-Pin CPGA
  • Product Categories:

    Lifecycle:Obsolete -

    RoHS: No RoHS

  • XC4028XLA-08HQ240I

    Manufacturer:Xilinx

  • FPGA XC4000XLA Family 28K Gates 2432 Cells 263MHz 0.35um Technology 3.3V 240-Pin HSPQFP EP
  • Product Categories:

    Lifecycle:Obsolete -

    RoHS: No RoHS

  • XC4028XLA-09HQ160C

    Manufacturer:Xilinx

  • FPGA XC4000XLA Family 28K Gates 2432 Cells 227MHz 0.35um Technology 3.3V 160-Pin HSPQFP EP
  • Product Categories: FPGAs

    Lifecycle:Obsolete -

    RoHS: No RoHS

  • XC5VLX155-2FF1760C

    Manufacturer:Xilinx

  • FPGA Virtex-5 LX Family 65nm Technology 1V 1760-Pin FCBGA
  • Product Categories: Rangée de condensateur

    Lifecycle:Active Active

    RoHS: No RoHS

  • XC5VLX155-2FFG1760C

    Manufacturer:Xilinx

  • FPGA Virtex-5 LX Family 65nm Technology 1V 1760-Pin FCBGA
  • Product Categories: FPGAs (Field Programmable Gate Array)

    Lifecycle:Active Active

    RoHS:

Need Help?

Support

If you have any questions about the product and related issues, Please contact us.