Motorola DSP Developer's Kit

Instantiating the Motorola DSP Simulator

A simulator library and executable exist for each supported Motorola DSP family.

Note    The MATLAB and Simulink MEX files supplied with the Motorola DSP Developer's Kit use a set of macros to implement the C++ style interface with the underlying Motorola DSP simulator. You are advised to use the macros provided (particularly if you intend to use INTERACTIVE mode). Alternatively, if you are familiar with C++, follow the C++ style instructions, also detailed in this chapter, on interfacing to the DSP simulator (i.e. the sim-> object references).

The simulator is run in the background by instantiating a MOTDSP_IssCustom class object or run interactively with the full simulator graphical user interface (GUI) by using the MOTDSP_IssStandAlone class. First, you must use the CREATE_SIMS macro outside of the try block to create the required simulator class. To switch between the two modes rebuild your MEX-file by using compiler directives. For example, the templates and supplied functions use STANDALONE.

Note    When running the simulator in INTERACTIVE mode, it is necessary to either run the loaded simulation or step through the code in order to obtain a non-zero output for that time step. Failure to perform this step will result in a discontinuity spike in the output data.

The constructors for each class are identical and take four string arguments:

• The name of the MEX function (not required when using the INSTANCE_SIMS macro)

The MEX_FUNC_NAME or S_MEX_FUNC_NAME user-defined macros would normally be used here, since they must be defined in the MEX-file.

• The name of the assembly or C-code binary, for example, "max-1r.cld"

This argument can simply be a string literal, but the MEX-file template examples provided also show the use of macros to help readability.

• The DSP device type, for example, "56309"

This argument represents a particular Motorola DSP device. If not specified (via an empty string, ""), the simulator defaults to the DSP56301 device or the DSP56602 device depending on the DSP family chosen.

• A simulator command file, for example, "mot_mult.cmd"

The name of the command file must be in lowercase and have a .cmd extension. If not specified for the MOTDSP_IssCustom object, the commands

break #1 END
go #1 

are inserted automatically by the Motorola DSP Developer's Kit and executed during simulation startup.

For example, use the INSTANCE_SIMS macro

INSTANCE_SIMS(      // name of assembly (or C) object file
                    "function.cld",
                    // DSP part name (eg, "56309")
                    "56309", 
                    // simulator startup file (not compulsory)
                    "my_setup.cmd"); 

or the C++ style instantiation

sim = new MOTDSP_IssCustom( /* MEX function name (the only
                                   additional parameter)     */
                           "MEX_FUNC_NAME", 
                           "function.cld",
                           "56309", 
                           "my_setup.cmd"); 

When the simulator is instantiated, it loads the assembly or C-code binary and reads its symbol information.

Instantiating Input and Output Objects

Running the Simulation