Embedded Target for Motorola MPC555

Summary of the Real-Time Target

Code Generation Options

The real-time target is an extension of the Real-Time Workshop Embedded Coder embedded real-time (ERT) target configuration. The real-time target inherits the code generation options of the ERT target, as well as the general code generation options of the Real-Time Workshop. These options are available via the Category menu of the Real-Time Workshop pane of the Simulation Parameters dialog box; they are documented in the Real-Time Workshop documentation and the Real-Time Workshop Embedded Coder documentation.

Some code generation options of the ERT target are not relevant to the real-time target, and are either unsupported, or restricted in their operation, by the PIL target. See Requirements and Restrictions for details.

Target-Specific Options

The real-time target has several target-specific code generation options. To view or change the setting of these options, select MPC555-DK (real-time) options from the Category menu of the Real-Time Workshop pane of the Simulation Parameters dialog box. This picture shows the options at their default settings.

The options are

• Optimize compiler for: This option controls compiler optimization switches used during the build process. The exact effect of the optimization switches depends on whether you are using the Diab or CodeWarrior compiler. You can optimize for performance via the speed option, or optimize for code size via the size option. If you select none, no optimization switches are invoked.
• Target memory model: Select either FLASH or RAM.

• If you select the FLASH option, files in a format suitable for downloading into the MPC555 on-chip flash memory are written. The naming convention for these files is model_flash.bin (code only), and model_flash.out (debugging symbols).

  If you select the RAM option, files in a format suitable for downloading into RAM is generated. The naming convention for these files is model_ram.srec (code only), and model_ram.out (code plus debugging symbols).

• Target scheduler: This option controls the scheduling algorithm used by the main program provided with the Embedded Target for Motorola MPC555. To understand this option, refer to
• The source code:
  matlabroot/toolbox/rtw/targets/mpc555dk/mpc555dk/mpc555dk_main.c
• The "Data Structures and Program Execution" section of the Real-Time Workshop Embedded Coder documentation.

The default option is SYNCHRONOUS_PIT_SCHEDULER. When you select this option, the main program operates as described in the "Data Structures and Program Execution" section of the Real-Time Workshop Embedded Coder documentation. The main() function installs rtOneStep as a timer interrupt service routine (ISR). The IRQ level for rtOneStep is specified by the RT_ONESTEP_IRQ_LEVEL parameter of the model's MPC555 Resource Configuration block (see MPC555 Resource Configuration). The main() function also sets the rate of the MPC555 Programmable Interrupt Timer (PIT) and enables timer interrupts.

If you select the USER_DEFINED_SCHEDULER option, the main() function does not install any ISR, and runs as an idle loop with optional calls to a background task. You must supply your own timer ISR and execution scheduler and modify mpc555dk_main.c accordingly.

Requirements and Restrictions

MPC555 Resource Configuration Block Required

To generate code from a model using the Embedded Target for Motorola MPC555 real-time target, an MPC555 Resource Configuration block must be included in the model. The MPC555 Resource Configuration block is required even for models that do not contain any MPC555 device driver blocks.

Note    When using device driver blocks from the Embedded Target for Motorola MPC555 libraries in conjunction with the MPC555 Resource Configuration block, do not disable or break library links on the driver blocks. If library links are disabled or broken, the MPC555 Resource Configuration block will operate incorrectly. See MPC555 Resource Configuration for further information.

Certain ERT code generation options are not supported by the real-time target. If these options are selected, the real-time target either ignores the option or issues an error message during the build process. Table 3-2 summarizes these restricted options.

Table 3-2: Real-Time Target Restricted Code Generation Options

Option	Restriction
MAT-file logging	Ignored if selected; build process proceeds
Create Simulink (S-function) block	Error if selected; build process terminates
External mode	Error if selected; build process terminates
Generate an example main program	This option should not be selected for the real-time target. The real-time target supplies a target-specific main program, mpc555dk_main.c.
Generate reusable code	Error if selected; build process terminates

Data Acquisition (DAQ) List Configuration

Algorithm Export and Code Analysis Reporting