This demo is targeted towards the EVBplus Dragon12-plus board, with 256 kB internal Flash EEPROM and 12 kB internal RAM.

To program the bootloader into the internal flash on the HCS12DG256 microcontroller, the P&E Micro USB BDM Multilink interface was used. However, this is not required if you have another means of programming the internal flash.

To compile the demo programs you can use the Freescale Codewarrior for HCS12(X) development environment.

Before the bootloader can be used, it needs to be built and programmed into the HCS12DG256's internal flash memory. The steps in this section only need to be done once.

When using Freescale Codewarrior, simply open the project from within Codewarrior and select Project→Make from the menu. The project file is located at: \Target\Demo\HCS12_Evbplus_Dragon12p_CodeWarrior\Boot\ide\

In case of build errors, refer to the information in section Resolving Build Errors.

The bootloader program is now ready to be programmed into the internal flash memory of the HCS12DG256. Using your favorite programmer, flash the bootloader using one of the following files, depending on what file type your programmer supports:

• \Target\Demo\HCS12_Evbplus_Dragon12p_CodeWarrior\Boot\bin\openblt_evbplus_dragon12p.abs
• \Target\Demo\HCS12_Evbplus_Dragon12p_CodeWarrior\Boot\bin\openblt_evbplus_dragon12p.abs.s19

The Microboot utility needs to be configured to connect to the correct COM-port and to communication at the correct baudrate:

• Start Microboot by double-clicking “\Host\MicroBoot.exe”.
• Click the “Settings”-button and select “OpenBLT using UART” from the dropdown box.
• Click the “Options”-button to configure the communication parameters.
  • Select the PC's COM-port that the board is connected to.
  • Set the baudrate to 57600 bits/sec.

Once you saved the settings by clicking the “OK”-button twice, you can close Microboot by clicking the “Cancel”-button on the main screen. Microboot is now ready for action!

When using Freescale Codewarrior, simply open the project from within Codewarrior and select Project→Make from the menu. The project file is located at: \Target\Demo\HCS12_Evbplus_Dragon12p_CodeWarrior\Prog\ide\

The output file is

• \Target\Demo\HCS12_Evbplus_Dragon12p_CodeWarrior\Prog\bin\demoprog_evbplus_dragon12p.abs.sx

To download this demoprog_evbplus_dragon12p.abs.sx file to the remaining flash memory using the bootloader, start the Microboot program and click the “Browse”-button. Browse to the “\Target\Demo\HCS12_Evbplus_Dragon12p_CodeWarrior\Prog\bin\” directory and select the demoprog_evbplus_dragon12p.abs.sx file to start the download.

Once the download completed, the newly programmed software will be started by the bootloader. You can verify this by checking that an LED blinks. Congratulations! That's all there is to using the bootloader.

When building the demo binaries for the first time, build errors might occur caused by CodeWarrior projects not correctly dealing with relative directories and having source-files in a project that have the same name as source-files in the library path. These errors are quickly resolved by removing the file from the project and adding them again.

Here is a list of encountered build errors and the solution of resolving the error:

• Could not open object file '.Target\Demo\HCS12_Evbplus_Dragon12p_CodeWarrior\Boot\ide\hcs12_Data\Standard\ObjectCode\datapage.c.o'
  • Delete the datapage.c file from the Boot\lib folder in the project and add it again. The source file is located at \Target\Demo\HCS12_Evbplus_Dragon12p_CodeWarrior\Boot\lib

• Could not open object file '.Target\Demo\HCS12_Evbplus_Dragon12p_CodeWarrior\Boot\ide\hcs12_Data\Standard\ObjectCode\mc9s12dg256.c.o'
  • Delete the mc9s12dg256.c file from the Boot\lib folder in the project and add it again. The source file is located at \Target\Demo\HCS12_Evbplus_Dragon12p_CodeWarrior\Boot\lib

• Cannot open .\Target\Demo\HCS12_Evbplus_Dragon12p_CodeWarrior\Boot\ide\hcs12_Data\Standard\ObjectCode\datapage.c.o
  • Delete the cstartup.c file from the Source\HCS12\CodeWarrior folder in the project and add it again. The source file is located at \Target\Source\HCS12\CodeWarrior

• Link error: Symbol AssertFailure in file .Target\Demo\HCS12_Evbplus_Dragon12p_CodeWarrior\Boot\ide\hcs12_Data\Standard\ObjectCode\main.c.o
  • Delete the assert.c file from the Source folder in the project and add it again. The source file is located at \Target\Source