From an experienced programmer perspective, the following notes taken from a real project using Renesas SH7047 will help you grasp the most important aspects in the use of Renesas microcontroller development tool HEW, the High-performance Embedded Workshop V4.

1. Create Organized Project Structure

It is a good practice to have a well-organized project structure rather than a flat structure. The project structure within HEW does not have to be the same as the project folder structure on your local drive, although it might be better that way.

Here is an example of my project structure in HEW.



Here is the project folder structure on my local drive

2. Add Project Files to Project Structure

Click menu Proejct->Add Files, browse to the files in the folders on your local drive, the assembly files and C files are added to the default folder Assembly source file and C source file under your HEW project respectively. Now drag-n-drop the files to the project subfolders as appropriate. Doing so does not change the location property of the files.

Note: Don’t create a header folder in your project and add the header files into it. The compiler will check the file dependencies and add them to the default Dependencies folder.

3. Toolchain Setting

All compiler and linker settings are done through the toolchain dialog, which is accessed through the menu Build->SuperH RISC Engine Standard Toolchain.

3.1 Setting Include File Path

You must set all include file path correctly otherwise the compiler will emit “couldn’t find file” error. When specify include file path as well as module path, use relative path instead of absolute path, which facilitates project relocation. Mostly relative to project directory is a good choice. An example is shown below.

3.2 Execution Start Address

Only if the execution start address is an externally defined symbol such as from library file or an absolute address, the start address needs specified. If it is a symbol in your file, the reset vector shall point to the symbol. Therefore, it is not necessary to specify the execution start address.

There are two methods to specify the start address when it is needed.

One method is use ENTRY command in a source file.
Example:
Entry = _crt0
Entry = 100

Another method is use the toolchain setting option.
Example:

3.3 Linker Section Command

Similar to a linker command file except some limitation, HEW uses a dialog for programmer to specify program sections. To set a code section into a specific memory area, you need to do two things. First, define a code section name by using #pragma directive.

Example:

#pragma section DUPVECT

void *Duplicate_RESET_Vectors[] =
{
      PowerON_Reset_PC,              // Power On Reset PC

      __secend("S"),                       // Power On Reset SP

      Manual_Reset_PC,                // Manual Reset PC

      __secend("S")                       // Manual Reset SP   
};

#pragma section ResetPRG

void PowerON_Reset_PC(void)
{ 
      //set the vector base register to the relocated address
      set_vbr((char *)&Duplicate_RESET_Vectors);

      //initialize B section to 0 and copies D section in ROM to R section in RAM
      _INITSCT();
     

      HardwareSetup();
      set_cr(SR_INIT);

      main();          //call C code entry
}

Secondly, specify the start address in the Section setting.

Note: after switching section, data section name becomes D<section name>