Active-HDL Interfaces Building VHPI Applications C Compilation Course 9

Active-HDL Interfaces

Building VHPI Applications C Compilation

Course 9

All materials updated on: September 30, 2005

9. Building VHPI Applications9. Building VHPI Applications

The VHPI interface provides a standard-compliant mechanism for connecting C applications to VHDL models simulated in Active-HDL. It allows development of applications such as:

• Code coverage tools• Design traversals• Behavioral C models• Custom debugging environments• C/C++ based testbenches


9.1 VHPI Tools in Active-HDL9.1 VHPI Tools in Active-HDL

All tools required to develop and debug VHPI applications are included in Active-HDL. Active-HDL includes:

• VHPI/PLI Wizard• C/C++ Editor• C/C++ Compiler (gcc)• C/C++ debugger (gdb)• Graphical front-end for gdb

VHPI applications can be compiled with any C/C++ compiler. However, gdb-compatible debug information is required for debugging VHPI applications in Active-HDL environment. (Debugging of C applications is described in course 10.)


This tutorial shows how to create a simple VHPI application. This application will be used in the datapath sample project delivered with Active-HDL. The application traverses the design hierarchy and counts the number of signals.

The tutorial covers:

9.2 Sample VHPI Application9.2 Sample VHPI Application

• Using VHPI/PLI Wizard• Entering C/C++ code in the editor• Configuring C/C++ build environment• Connecting VHPI application to the VHDL

model (the datapath sample)


9.3 Loading VHDL Design9.3 Loading VHDL Design

1. Choose Open Workspace/Design Explorer from the File menu. Then, double-click the datapath workspace icon located in the \Samples\VHDL_Designs folder.


9.4 Compiling the Design9.4 Compiling the Design

2. Compile the design using the Compile All command from the Design menu.

3. Use the list box in the Design Browser to set top_testbench (tb_architecture) as the top-level unit.


9.5 Running the Wizard9.5 Running the Wizard

4. Start the wizard with the VHPI/PLI Wizard command from the Tools menu.

5. Type dump_hierarchy in the VHDL Procedure/Function/ Architecture Name field. Uncheck the Generate VHPI Interface Template option and set the remaining options as shown in the figure on the right.

6. Press Add Item to List, then Generate, and close the window by clicking OK.


9.6 Reviewing Created Files9.6 Reviewing Created Files

7. Review the list of files created by the wizard. The list is printed into the Console window.

# Design: Created file C:\My_Designs\Samples\Datapath\src\VHPI\vhpiuser_aldec.cpp

# Design: Created file C:\My_Designs\Samples\Datapath\src\VHPI\dump_hierarchy_vhpi.h

# Design: Created file C:\My_Designs\Samples\Datapath\src\VHPI\dump_hierarchy_vhpi.cpp

# Design: Created file C:\My_Designs\Samples\Datapath\src\VHPI\dump_hierarchy_vhpi.vhd

The files are also visible in the VHPI folder in the Design Browser.Also a DLM C/C++ configuration file is automatically added for building the application.


9.7 Editing C Code9.7 Editing C Code

8. The dump_hierarchy_vhpi.cpp file contains an empty body of the dump_hierarchy_exec function.

The following slides show complete code for the modified dump_hierarchy_vhpi function and for an auxiliary traverse_hierarchy routine.

Before editing the functions add the following #include directive to the beginning of the dump_hierarchy_vhpi.cpp file:

#include <stdio.h>


9.8 dump_hierarchy_vhpi function9.8 dump_hierarchy_vhpi function

vhpiHandleT rootInstHdl = NULL; // handler to rootInst component

vhpiHandleT iteratorSigHdl = NULL; // iterator for SigDecls

vhpiHandleT Hdl = NULL; // handler

vhpiHandleT archBodyHdl = NULL; // handler to archBody

vhpiHandleT entityDeclHdl = NULL; // handler to entityDecl

int numObjs = 0; // initialize objects counter

vhpi_printf("\nUsing VHPI application as Foreign Architecture to count declared signals...");

//1.

if ( rootInstHdl = vhpi_handle(vhpiRootInst, NULL) ){

//2

// signal declarations

if ( iteratorSigHdl= vhpi_iterator(vhpiSigDecls, rootInstHdl) )

//3.

while ( Hdl = vhpi_scan(iteratorSigHdl) ){

// handler points to object of type vhpiSignalDeclK (signal)

vhpi_printf("found signal: %s ", // signal name

vhpi_get_str(vhpiNameP, Hdl));

numObjs++;

}

// CONTINUED ON NEXT SLIDE

Replace the // put your code here comment in procedure dump_hierarchy_exec in the dump_hierarchy_vhpi.cpp file with following code:


9.8. dump_hierarchy_vhpi (continued)9.8. dump_hierarchy_vhpi (continued)

traverse_hierarchy(rootInstHdl, &numObjs);

// fetching some information about analyzed design:

// name of architecture of top level design

if ( archBodyHdl = vhpi_handle(vhpiDesignUnit, rootInstHdl) ){

// name of entity of top level design

if ( entityDeclHdl = vhpi_handle(vhpiPrimaryUnit, archBodyHdl) ){

vhpi_printf("===============================================");

vhpi_printf("SUMMARY:");

vhpi_printf("Analyzed entire design '%s' contains %d signal(s)",vhpi_get_str(vhpiNameP, entityDeclHdl), numObjs);

}

}

}

vhpi_printf("\nEnd of Your VHPI application.......");

(function defined in the dump_hierarchy_vhpi.cpp file continued)


9.9 traverse_hierarchy function 9.9 traverse_hierarchy function

PLI_VOID traverse_hierarchy(vhpiHandleT ScopeHdl, int *numObjs){

vhpiHandleT iteratorSigHdl = NULL; // iterator for SigDecls

vhpiHandleT iteratorRegHdl = NULL; // iterator for InternalRegions

vhpiHandleT Hdl = NULL; // handler

vhpiHandleT SigHdl = NULL; // handler

if (ScopeHdl==NULL) return;

if ( iteratorRegHdl = vhpi_iterator(vhpiInternalRegions, ScopeHdl) )

//1.

while ( Hdl = vhpi_scan(iteratorRegHdl) ){

//2.

vhpi_printf("%s [%d]: %s ",vhpi_get_str(vhpiKindStrP, Hdl),

vhpi_get(vhpiKindP, Hdl),

vhpi_get_str(vhpiNameP, Hdl) );

// signal declarations

if (iteratorSigHdl= vhpi_iterator(vhpiSigDecls, Hdl))

//3.

while ( SigHdl = vhpi_scan(iteratorSigHdl) ){

// handler points to object of type vhpiSignalDeclK (signal)

vhpi_printf("found signal: %s ", //signal name

vhpi_get_str(vhpiNameP, SigHdl));

(*numObjs)++;

}

traverse_hierarchy(Hdl, numObjs);

}

}

Above the dump_hierarchy_exec function type the following code:


9.9a CPP file contents 9.9a CPP file contents


9.10 Creating the Foreign Architecture

9.10 Creating the Foreign Architecture

9. VHPI applications can be registered by using foreign subprograms or foreign architectures. This tutorial shows how to register the VHPI application by using the foreign architecture.Edit the dump_hierarchy_vhpi.vhd to include the code shown below:

After editing, check if the new code compiles correctly.

entity dump_hierarchy is

end entity dump_hierarchy;

architecture dump_hierarchy of dump_hierarchy is

attribute foreign of dump_hierarchy : architecture is

"VHPI $dsn\src\VHPI\datapath.dll;dump_hierarchy_model";

begin

end architecture dump_hierarchy;


9.11 Instantiating the Foreign Architecture

9.11 Instantiating the Foreign Architecture

10. The dump_hierarchy architecture created on the previous slide has to be instantiated in the top-level unit. The neighboring pictures show component declaration and instantiation in the testbench.vhd file.


9.12 C/C++ Configuration9.12 C/C++ Configuration

11.Double click on the C/C++ Configuration file $DSN/VHPI/datapath.dlm. The C/C++ configuration dialog allows to specify all options required to build the VHPI application. Verify that the settings are the same as shown in the picture below.


9.13 C/C++ Compilation9.13 C/C++ Compilation

12. Click datapath.dlm with the right mouse button and choose Build from the context menu. The VHPI library (datapath.dll) will be built.


9.14 Running the Simulation9.14 Running the Simulation

13. Recompile HDL files. (Two files were edited during previous tutorial steps.)

14. Choose Initialize Simulation from the Simulation menu. The VHPI application will be registered through the VHDL foreign architecture. This is reported to the Console window.# KERNEL: PLI/VHPI kernel's engine initialization done.

# VHPI: Loading library 'C:\My_Designs\Samples\Datapath\src\VHPI\datapath.dll'

# : Using VHPI application as Foreign Architecture to count declared signals...

# VHPI: found signal: CLK

# VHPI: found signal: RESET

# VHPI: found signal: START

# VHPI: found signal: CODE

# VHPI: found signal: DATA_IN

...

When the scan is complete, the design is ready for simulation.

The VHPI application starts analyzing the design and prints collected information to the Console window.

Documents

Active-HDL Interfaces Building VHPI Applications C Compilation Course 9