www.gusucode.com > rtwdemos 工具箱matlab源码程序 > rtwdemos/rtwdemo_pcgd_stage_2_p1_script.m
%% Configuring the Data Interface
% This example shows how to specify signals and parameters for inclusion in
% generated code.
%
% *Time:* 45 minutes
%
% *Goals*
%
% Learn how to control the following attributes of signals and parameters
% in the generated code:
%
% * Name
% * Data type
% * Data storage class
%
% <matlab:RTWDemos.pcgd_open_pcg_model(2,0); *Task:* Open the model.>
%% Background: Declaration of Data
% Most programming languages require that you _declare_ data and functions
% before using them. The declaration specifies:
%
% * Scope - The region of the program that has access to the data
% * Duration - The period during which the data is resident in memory
% * Data type - The amount of memory allocated for the data
% * Initialization - A value, a pointer to memory, or NULL
%
% The combination of scope and duration is the _storage class_. If you do not
% provide an initial value, most compilers assign a zero value or a null pointer.
%
% Supported data types include:
%
% * |double| - Double-precision floating point
% * |single| - Single-precision floating point
% * |int8| - Signed 8-bit integer
% * |uint8| - Unsigned 8-bit integer
% * |int16| - Signed 16 bit integer
% * |uint16| - Unsigned 16 bit integer
% * |int32| - Signed 32 bit integer
% * |uint32| - Unsigned 32 bit integer
% * Fixed Point - 8-, 16-, 32-bit word lengths
%
% Supported storage classes include:
%
%%
%
%
% Name Description Parameters Signals Data
% Supported Supported Types
%
% Const Use const type qualifier in declaration Y N All
%
% ConstVolatile Use const volatile type qualifier in Y N All
% declaration
%
% Volatile Use volatile type qualifier in declaration Y Y All
%
% ExportToFile Generate and include files, with Y Y All
% user-specified name, containing global
% variable declarations and definitions
%
% ImportFromFile Include predefined header files containing Y Y All
% global variable declarations
%
% Exported Global Declare and define variables of global Y Y All
% scope
%
% Imported Extern Import a variable that is defined outside Y Y All
% of the scope of the model
%
% BitField Embed boolean data in a named bit field Y Y Boolean
%
% Define Represent parameters with a #define macro Y N All
%
% Struct Embed data in a named struct to Y Y All
% encapsulate sets of data
%
%% Controlling Data in Simulink(R) and Stateflow(R)
% Two methods are available for declaring data in Simulink(R) and Stateflow(R): _data
% objects_ and _direct specification_. This example uses the data object
% method. Both methods allow full control over the data type and storage
% class. You can mix the two methods in a single model.
%
% You can use data objects in a variety of ways in the MATLAB(R) and Simulink(R)
% environment. The example focuses on three types of data objects.
%
% * Signal
% * Parameter
% * Bus
%
% The code generator uses data objects from the MATLAB base workspace. You
% can create and inspect them by entering commands in the MATLAB Command Window
% or by using the Model Explorer.
%
% The following example shows the definition of Simulink(R) signal object
% |pos_cmd_one|:
%
% <<data_objects_MATLAB.jpg>>
%
% You can open the Model Explorer and display details about a specific data
% object in the example model.
%
% Click each of the following object names:
%
% * <matlab:RTWDemos.pcgd_open_dialog('pos_cmd_one','',2) |pos_cmd_one|> - Top-level output, Double, Exported Global
% * <matlab:RTWDemos.pcgd_open_dialog('pos_rqst','',2) |pos_rqst|> - Top-level input, Double, Imported Extern Pointer
% * <matlab:RTWDemos.pcgd_open_dialog('P_InErrMap','',2) |P_InErrMap|> - Calibration parameter, Auto, Constant
% * <matlab:RTWDemos.pcgd_open_dialog('ThrotComm','',2) |ThrotComm|(1)> - Top-level output structure, Auto, Exported Global
% * <matlab:RTWDemos.pcgd_open_dialog('ThrottleCommands','',2) |ThrottleCommands|(1)> - Bus definition, Struct, None
%
% (1) |ThrottleCommands| defines a Simulink(R) Bus object,
% |ThrotComm| is the instantiation of the bus. If the bus is a nonvirtual
% bus, the signal will generate a structure in the C code.
%
% As in C, you can use a bus definition (|ThrottleCommands|) to instantiate
% multiple instances of the structure. In a model diagram, a bus object
% appears as a wide line with central dashes, as shown below.
%
% <<BusObjectLine.jpg>>
%
% The following figure shows the Model Explorer display if you click the
% signal name |pos_rqst|:
%
% <<show_storage_class_pos_rqst.jpg>>
%
% A data object has a mixture of _active_ and _descriptive_ fields. Active
% fields affect simulation or code generation. Descriptive fields do not
% affect simulation or code generation, but are used with data
% dictionaries and model-checking tools.
%
% *Active Fields*
%
% * Data type
% * Storage class
% * Value (parameters)
% * Initial value (signals)
% * Alias (define a different name in the generated code)
% * Dimension (inherited for parameters)
% * Complexity (inherited for parameters)
%
% *Descriptive Fields*
%
% * Minimum
% * Maximum
% * Units
% * Description
%
%% Adding New Data Objects
% You can create data objects for named signals, states, and parameters.
% To associate a data object with a construct, the construct must have a
% name.
%
% The Data Object Wizard is a tool that finds constructs for which you
% can create data objects, then creates the objects for you. The example
% model includes two signals that are not associated with data objects:
% |fbk_1| and |pos_cmd_two|.
%
% To find the signals and create data objects for them:
%
% 1. <matlab:dataobjectwizard('rtwdemo_PCG_Eval_P2') *Task:* Open the Data Object Wizard.>
%
% <<data_object_wiz.jpg>>
%
% 2. Click *Find* to find candidate constructs.
%
% 3. Click *Select All* to select all candidates.
%
% 4. Click *Apply Package* to apply the Simulink(R) package for the data
% objects.
%
% 5. Click *Create* to create the data objects.
%
%% Configuring Data Objects
% The next step is to set the data type and storage class.
%
% *1.* Click the following object names to edit the data objects:
%
% * <matlab:RTWDemos.pcgd_open_dialog('fbk_1','',2) |fbk_1|>, Double, Imported Extern
% * <matlab:RTWDemos.pcgd_open_dialog('pos_cmd_two','',2) |pos_cmd_two|>, Double, Exported Global
%
% Clicking a name opens the Model Explorer to show the base workspace.
%
% 2. For each object listed in the preceding table, click the signal name in
% the *Contents* pane.
%
% 3. Change the field settings in the *Data* pane to match those in the table.
%
% *Note:* If the Model Explorer does not open for either of the two signals,
% repeat the steps in *Adding New Data Objects*.
%
%% Controlling File Placement of Parameter Data
% Embedded Coder(R) allows you to control the files in which the
% parameters and constants are defined. For the example model, all parameters
% were written to the file |eval_data.c|.
%
% To change the placement of parameter and constant definitions, set the appropriate
% data placement options for the model configuration. Within the
% Model Explorer, you set the options at *Configuration > Code Generation > Data Placement*. For the example, the model has already been
% configured.
%
% 1. <matlab:RTWDemos.pcgd_open_dialog('RTW','DAT',2) *Task:* Open the *Data Placement* pane of the Configuration Parameters dialog.>
%
% 2. Enter data in the *Data Placement* pane as shown in the following figure:
%
% <<DataPlacmentDialog.jpg>>
%
% The generated code that results for |eval_data.c| is shown below.
%
% <<eval_data_file.jpg>>
%
%% Enabling Data Objects in Generated Code
% The next step is to ensure that the data objects you have created appear
% in the generated code. To enable parameters in generated code, set the *Inline parameters*
% option for the model configuration. In the Model Explorer, this option is:
%
% *Configuration > Optimization > Signals and Parameters > Simulation and code generation > Inline
% parameters*
%
% <<Sim_And_Code_Gen_Optimizations.jpg>>
%
% <matlab:RTWDemos.pcgd_open_dialog('OPT','',2) *Task:* Set the *Inline parameters* option.>
%
% To enable a signal in generated code:
%
% 1. Right-click the signal line.
%
% 2. From the context menu, select *Signal Properties*. A Signal Properties dialog
% box appears.
%
% 3. Make sure the option *Signal name must resolve to a Simulink signal
% object* is selected.
%
% <<signal_object.jpg>>
%
% You can enable signals associated with data objects individually, or you
% can enable all such signals in a model at once by entering
% |disableimplicitsignalresolution| in the MATLAB Command Window.
%
% <matlab:disableimplicitsignalresolution(pcgDemoData.Models{2}) *Task:* Enable all signals with associated data objects.>
%
%% Effects of Simulation on Data Typing
% For the example model, all data types are set to |double|. Since Simulink(R) uses
% the |double| data type for simulation, no changes are expected in the
% model behavior when you run the generated code. To
% verify this, run the test harness model. The test harness model is
% automatically updated to include the rtwdemo_PCG_Eval_P2 model. That is the only
% change made to the test harness.
%
% <matlab:RTWDemos.pcgd_open_pcg_model(2,1); *Task:* Open the test harness.>
%
% <matlab:RTWDemos.pcgd_runTestHarn(1,2) *Task:* Run the test harness.>
%
% The resulting plot shows that the difference between the golden and simulated
% versions of the model remains zero.
%
% <<FirstPassTest.jpg>>
%
%% Viewing Data Objects in Generated Code
% Now view the file |rtwdemo_PCG_Eval_P2.c| to see how the use of data objects changed
% the generated code.
%
% <matlab:RTWDemos.pcgd_buildDemo(2,0) *Task:* Generate code for the model.>
%
% Click the following file names to view generated code:
%
% * <matlab:RTWDemos.pcgd_showSection(2,'func'); |rtwdemo_PCG_Eval_P2.c|> - Provides step and initialization function. Uses the defined data objects.
% * <matlab:RTWDemos.pcgd_showSection(2,'eval_data_c'); |eval_data.c|> - Assigns values to the defined parameters. Has the file name specifically defined.
% * <matlab:RTWDemos.pcgd_showSection(2,'eval_data_h'); |eval_data.h|> - Provides extern definitions to the defined parameters. Has the file name specifically defined.
% * <matlab:RTWDemos.pcgd_showSection(2,'ert_main'); |ert_main.c|> - Provides scheduling functions.
% * <matlab:RTWDemos.pcgd_showSection(2,'data_def'); |rtwdemo_PCG_Eval_P2.h|> - Defines data structures. Using data objects, shifted some parameters out of this file into |user_data.h|.
% * <matlab:RTWDemos.pcgd_showSection(2,'private'); |PCG_Eval_p2_private.h|> - Defines private (local) data for the generated functions. Objects now defined in |eval_data| were removed.
% * <matlab:RTWDemos.pcgd_showSection(2,'func_types'); |rtwdemo_PCG_Eval_P2_types.h|> - Defines the model data structure.
% * <matlab:RTWDemos.pcgd_showSection(2,'rtwtypes'); |rtwtypes.h|> - Provides mapping to data types defined by Simulink(R) Coder(TM). Used for integration with external systems.
%
% The following figure shows the code for function |rtwdemo_PCG_Eval_P2_step| as it appears
% in |rtwdemo_PCG_Eval_P2.c| before the use of data objects:
%
% <<wo_data_objects.jpg>>
%
% The figure below shows the code as it appears in |rtwdemo_PCG_Eval_P2.c| with
% data objects.
%
% <<WithDataObjects.jpg>>
%
% This figure shows that most of the Simulink(R) Coder(TM) data structures have been
% replaced with user-defined data objects. The local variable |rtb_Sum2| and the
% state variable |rtwdemo_PCG_Eval_P2_DWork.Discrete_Time_Integrator1_DSAT|
% still use the Simulink(R) Coder(TM) data structures.
%
%% Data Management
% Data objects exist in the MATLAB base workspace. They are
% saved in a separate file from the model.
% To save the data manually, enter |save| in the MATLAB Command Window.
%
% The separation of data from the model provides many benefits.
%
% *One model, multiple data sets*
%
% * Use of different data types to change the targeted hardware (for example, for floating-point and fixed-point targets)
% * Use of different parameter values to change the behavior of the control algorithm (for example, for reusable components with different calibration values)
%
% *Multiple models, one data set*
%
% * Sharing of data between Simulink(R) models in a system
% * Sharing of data between projects (for example, transmission, engine, and wheel controllers might all use the same CAN message data set)
%
%% Further Study Topics
%
% * <matlab:helpview([docroot,'/toolbox/simulink/helptargets.map'],'sl_data'); Data types, including fixed-point data, data objects, and data classes>
% * <matlab:helpview([docroot,'/toolbox/ecoder/helptargets.map'],'custom_storage_classes'); Custom storage classes>
% * <matlab:helpview([docroot,'/toolbox/ecoder/helptargets.map'],'data_placement'); Managing file placement of data definitions and declarations>
%
% Copyright 2007-2012 The MathWorks, Inc.