Creating HDL Text Modules, страница 8

2.23   Creating Fub Contents

•  Save your state diagram by pressing Ctrl+S or choosing the      button on the toolbar

•  Right-click on the Control.ASF file in the Design Browser and select the Compile option. Watch as the VHDL code is generated from the state diagram and then compiled

•  Active-HDL automatically creates corresponding VHDL code for the state machine. To open the Control.vhd file in the HDL Editor window, double click its name.

•  Compile the top level block diagram (top_counter.bde)

2.24   Creating Fub Contents

•  The HDL Editor window contains the code for the state machine and highlights the syntax to increase readability.

•  You can also generate the structure for the code to ease navigation.

•  For more details on the HDL Editor, please refer to the Bottom-Up Design Methodology course

2.25   Creating Graphical Process/Always

•  These elements create another level of abstraction in the Active-HDL projects.

•  The Graphical Process/Always text blocks are the objects that allow users to add another form of the description in designs based on block diagrams.

•  By creating special text blocks representing VHDL processes or Verilog always statements, statements can be placed directly on a block diagram in the same way as other typical HDL statements.

•  They can be edited and wired and the list of connected signals/nets to the symbol is automatically updated and displayed within the object frame visible in the block diagram window.

•  Graphical Process and Graphical Always can be edited directly in the Block Diagram Editor window or in the standalone HDL Editor window.

2.26   Objects View

•  The Objects View option allows you to view, sort and change properties of all objects defined in a block diagram e.g. terminals, signals, generics, parameters, statements.

•  The objects listed within this window can be put in the user-defined order by using the drag and drop technique.

•  They can also be sorted in ascending or descending order or with the default settings.

•  The final order applied by the user is used while generating a code.

•  Additionally, the Objects View window allows the user to follow signals/net and processes specified on block diagrams.


2.27   Multiple architectures support

•  The Block Diagram Editor allows the user to generate the VHDL code that contains an architecture body only.

•  In this way, you can create and use different implementations (several architectures) for the same entity.


                                       2.28 Visible Port Direction

•  The purpose of this feature is to make the port direction visible on a block diagram.

•  It makes the analysis of a block diagram easier especially when it contains a large number of complex symbols that have different types of ports located on the left and right side of the symbol.

2.29  Cross-probing between Block Diagram Editor and generated HDL code

•  The Show in Generated Code is available in context menu of selected object in the block diagram window.

•  The Block Diagram Editor supports cross-probing between a diagram and the generated code.

•  It allows to link diagram objects (e.g. wires, buses, components, graphical processes / always , other HDL statements) with the HDL code and to see the declaration of the selected object from a diagram directly in the code.

                                           2.30  Bitmap support

•  The Block Diagram Editor allows the user to place on a block diagram a picture (e.g. company's logo) from the bitmap file

The Block Diagram Editor supports the

following picture formats:

•  Bitmap files (*.bmp)

•  Windows Metafile files (*.wmf)

•  Enhanced Metafile files (*.emf)

                                      2.31  Comments for diagram elements