1.2.1 SAM E54 Xplained Pro Evaluation Kit: Building and Running the I²C Fail Safe Bootloader

Path of the application within the repository is apps/i2c_fail_safe_bootloader/.

To build the application, refer to the following table and open the project using its IDE.

• SAM E54 Xplained Pro Evaluation Kit is used for both Host development kit and Target development kit

  

• Connect the I²C SDA line Pin 11 (SERCOM7 PAD/PD08) on EXT3 of the Host development kit to the I²C SDA line Pin 11 (SERCOM3 PAD/PA22) on EXT1 of the Target development kit

• Connect the I²C SCL line Pin 12 (SERCOM7 PAD/PD09) on EXT3 of the Host development kit to the I²C SCL line Pin 12 (SERCOM3 PAD/PA23) on EXT1 of the Target development kit

• Connect a ground wire between the Host development kit and Target development kit

• Connect the Debug USB port on the Host development kit to the computer using a micro USB cable

• Connect the Debug USB port on the Target development kit to the computer using a micro USB cable

1. Open the bootloader project bootloader/firmware/sam_e54_xpro.X in the IDE.

2. Build and program the application using the IDE on to the Target development kit.

   • LED0 will be turned-on to indicate that bootloader code is running on the target
   • LED0 will also turn on when the bootloader does not find a valid application; i.e., the first word of the application (stack pointer), contains 0xFFFFFFFF

3. Open the NVM host application project host_app_nvm/firmware/sam_e54_xpro.X in the IDE.

4. Build and program the NVM host application using the IDE on to the Host development kit.

   • The prebuilt combined bootloader and application HEX header file host_app_nvm/firmware/src/test_app_images/image_pattern_hex_sam_e54_xpro_bootloader_app_merged.h will be programmed to the Target development kit

   • This must be programmed once to program both bootloader and application into the inactive Flash bank

5. Open the Terminal application (e.g., Tera Term) on the computer.

6. Configure the serial port settings for Target development kit as follows:

   • Baud: 115200
   • Data: 8 Bits
   • Parity: None
   • Stop: 1 Bit
   • Flow Control: None

7. Press the Switch SW0 on the Host development kit to trigger programming of the binary.

8. Once the programming is complete:

   • LED0 on the Host development kit will be turned on indicating success

   • LED0 on the Target development kit should start blinking and the user should see below output on the console

     • The NVM Flash Bank can be BANK A or BANK B based on from where the test application is running

   

   

9. Press and hold the Switch SW0 on the Target development kit to trigger Bootloader from test application.

   • This is to program the application binary in other bank and the user should see below output

   

10. To program the prebuilt application image host_app_nvm/firmware/src/test_app_images/image_pattern_hex_sam_e54_xpro.h to the inactive bank of Target development kit, open the user.h file of the NVM host application project host_app_nvm/firmware/sam_e54_xpro.X as shown below:

    

11. In the user.h file update the APP_HEX_HEADER_FILE and APP_IMAGE_START_ADDR values as mentioned below.

    #define APP_HEX_HEADER_FILE         "test_app_images/image_pattern_hex_sam_e54_xpro.h"
    
    #define APP_IMAGE_START_ADDR        0x82000UL

    

    • APP_HEX_HEADER_FILE: Relative path to the generated header file containing the application hex image in an array
    • APP_I2C_SLAVE_ADDR: I²C client address
    • APP_ERASE_PAGE_SIZE: Erase page size of the target (target = MCU being programmed)
    • APP_PROGRAM_PAGE_SIZE: Program page size of the target (target = MCU being programmed)
      • The macro can either be set to the program page size or can be set to the size of the erase page size of the target
      • In the demo example, the macro is set equal to the size of the erase page
      • On embedded host where RAM is limited, the macro may be set to the actual program page size to reduce the RAM used to hold the program data
    • APP_IMAGE_START_ADDR: User application start address
      • It must be set to 0x80000UL when programming the combined bootloader and application binary to the inactive bank
      • It must be set to 0x82000UL when programming the application binary only to the inactive bank

12. Build and program the NVM host application using the IDE on to the Host development kit.

13. On the Target development kit (the board being programmed), press and hold the Switch SW0 and then press Reset button or Power cycle to force trigger bootloader at startup.

    • LED0 will be turned-on to indicate that bootloader code is running on the target

14. Press Reset button on the Host development kit to program the application binary.

15. Repeat Steps 7-8 once.

    • The user should see other Bank in console displayed compared to first run