2.1.1 Blink LED Application Getting Executed from QSPI Flash on SAMA7G54 Evaluation Kit

Description

This application demonstrates how to run and debug an application executed from QSPI flash on SAMA7G54 Evaluation kit. Blue LED turns ON when user input key(sw1) is pressed.

Key Highlights of SAMA7G54 Evaluation Kit

• 2-lane MIPI-CSI2 (D-PHY)
• 12-bit RGB camera
• Dual Ethernet (Gigabit and 10/100)
• Audio sub-system
• 2 SSC and 2 I2SMCC
• 2x 4-channel PDMs (up to 8 microphones)
• 6 CAN-FD
• 3 High-Speed USB ports
• 12 FLEXCOMs (USART, SPI, TWI)
• 1Gb Octal SPI Flash
• 2 EEPROMs w/ EUI-48TM MAC ID
• 1 SD card slot
• 2 Ethernet ports (Gigabit and 10/100)
• Pad for ATWILC3000 Wi-Fi/BT module (unpopulated)
• 40-pin Raspberry Pi expansion header
• 2 mikroBUS connectors

Modules/Technology Used

Peripheral Modules

• BSP

  

Hardware Used

• SAMA7G54 Evaluation kit.
• SD Card.

Software/Tools Used

• MPLAB® X IDE.
• MPLAB® XC32 Compiler.
• MPLAB® Code Configurator (MCC).

This project has been verified to work with the following versions of software tools:

Refer Project Manifest present in harmony-manifest-success.yml under the project folder firmware/src/config/default to know the MPLAB® X IDE, MCC Plugin, libraries version.

Hardware Setup

• Power up the board by connecting 5V/2A power adapter to J1 or connect the USB Micro-B port(J7) to the Host PC using a micro-USB cable.
• Connect the USB Micro-B port (J24- J-Link-CDC) on board to the computer using a micro-USB cable (to print debug messages on the serial console).
• Default jumper settings should be as follows:

  

  

• Press the start button(nSTART switch) on the board.

Developing an Application Executed from QSPI Flash Memory

1. Launch MPLAB® X IDE. From the main menu, click on File, then New Project. Under Projects choose Application Project(s).

   

2. In the Select Device window, for Family select 32-bit MCUs (PIC32C/SAM), for Device select SAMA7G54. Click Next.

   

   In the Select Compiler window, for Compiler Toolchains select XC32 COMPILER, and Click Next.

   

3. Enter Project Location , Project Folder and Project Name. Click Finish.
4. After the project is created, MCC will be automatically launched. (To launch MCC manually, from main menu, click on Tools -> Embedded -> MPLAB® Code Configurator or click MCC button in the MPLAB® X IDE tool bar). It will launch Content manger Wizard. Then, select MPLAB® Harmony.

   

5. In addition to the required packages, download the optional packages bsp, csp, core, dev_packs and then click Finish. Content download will take some time. Wait till all the contents are downloaded.

   

6. A project graph will be displayed. From Device Resource add Board Support Packages for SAMA7G5 Evaluation kit BSP to Project Graph.

   

7. Ensure all the pins are configured as below:

   PA13, PB8, PD20 are for LEDs green, red and blue respectively. PA12 is configured for user button.

   Configure the pins PB9-PB21 for QSPI as mentioned in the below image.

   

8. Save all and then click Generate Code. This will generate code for all the Device Resource that have been added in the project graph.

   

9. Up to this point in the project creation process, the user used MPLAB Code Configurator(MCC) to configure and generate code to initialize the device (SAMA7G54) .

   Refer initialization.c in project_directory/src/config folder to find all the device resource added in the project graph got initialized. All that is left is for the user to write the application code in the main.c file. Documentation for each of the peripheral libraries or bsp libraries can be accessed as follows:

   1. Peripheral libraries APIs can be accessed as a HTML file (*.html) from the Harmony 3 Framework path. (/framework_path/csp/docs/index.html)
   2. BSP libraries APIs can be found in bsp.h
10. APIs used for this application are as follows:
    • LED_BLUE_On();
    • LED_BLUE_Off);
    • USER_BUTTON_Get();
11. Sample code can be found in main.c under project_directory/src folder.
12. Right click on the project and click Properties. For Connected Hardware Tool -> select connected hardware debugger used, for Compiler Toolchain -> select XC32 and click Apply.

    

13. From J-32/J-Link, Option categories choose Communication and for JTAG Method, select 4-wire JTAG.

    

14. Select Bootstrap for Categories and select the Use Bootstrap checkbox. For bootstrap file -> select the at91bootstrap elf file from the project_directory, Click on Apply and OK.

    

15. By default, MPLAB X only produces ELF and Hex format output files. To generate application output in binary format, a post build step needs to be added to the project properties. To do this, go to project properties, building, click the check box Execute this line after build, then enter the below command.

    ${MP_CC_DIR}/xc32-objcopy -O binary ${DISTDIR}/${PROJECTNAME}.${IMAGE_TYPE}.elf ${DISTDIR}/harmony.bin

    

Linker File Modifications to Execute an Application from QSPI Flash (Offset 0x40000)

In this example the user has demonstrated an application getting executed from QSPI flash offset 0x40000.

The following linker file(ddr.ld) modifications are required to enable application getting executed from QSPI:

1. Define only two memory regions:

   

2. Assign text section to rom(qspi) and data section to relocate section(so, it will be copied from qspi to sram during runtime).

   

3. Remove cache aligned sections and assign _ramcode_lma and _ramdata_lma to ram as shown below.

   

4. Sample linker file can be found in the project_directory.
5. Its a good practice to remove unused input section while building output binary. To do this, go to project properties , xc32-ld config , check Remove Unused Sections as shown below.

   

6. Clean and build the project. The user should see a message on the output console that the project was successfully built. This completes the development of the application.

   The harmony.bin file can be found in the /project_directory/dist/default/production/harmony.bin.

SAM-BA Installation and Setup

Install SAM-BA tool on Windows host PC:

1. To Download the latest version of SAM-BA tool for Windows click this link.
2. Download the ZIP file and unzip it into a working directory of the choice.
3. Add the SAM-BA directory path to the environment variables.
   • To do this from the PC --> Open the Start Search, type in env.
   • Choose Edit the system environment variables --> Click Environment Variables --> System Variables --> add SAM-BA directory path to path variables.

     

4. Once the SAM-BA Host program has been installed, the execution of the application is from the Windows command prompt.

Setup to flash using SAM-BA:

1. Open Disable boot Jumper(J22) on SAMA7G54 Evaluation Kit.
2. Ensure there is no SD memory card inserted and there is no application on any of the external NVMs.
3. Press start button.
4. Push and hold the BOOT_DIS button.(This disables booting from the onboard memories - NAND and NOR(QSPI) flash Memory)
5. Reset the board by pressing and then releasing the reset nRST button.
6. Release the BOOT_DIS button.

   

Configure First Stage Bootloader to Boot from QSPI Flash

Use the below SAM-BA commands to configure first stage bootloader to boot from QSPI. To learn about the boot process and first stage boot configuration, refer section Boot Strategies of the SAMA7G5 Series Data Sheet (DS60001765).

• sam-ba -p j-link -b sama7g5-ek -a bootconfig -c writecfg:bscr:EMULATION_ENABLED // Enable Emulation
• sam-ba -p j-link -b sama7g5-ek -a bootconfig -c readcfg:bscr // Read bscr and verify emulation is enabled
• sam-ba -p j-link -b sama7g5-ek -a bootconfig -c resetemul // Emulation SRAM Reset
• sam-ba -p j-link -b sama7g5-ek -a bootconfig -c refreshcfg:emul //Refresh Emulation SRAM.
• sam-ba -p j-link -b sama7g5-ek -a bootconfig -c writecfg:bcp-emul:DBGU,QSPI0_IOSET1 // Enable debug, QSPI0 as external NVM
• sam-ba -p j-link -b sama7g5-ek -a bootconfig -c readcfg:bcp-emul // Read bcp_emul and verify whether QSPI is set as external NVM

  

  Then, reset the board by pressing reset button.

  Note: Boot configuration using Emulation SRAM has to be set every power cycle.

  User can also write boot configuration packet(BCP) to OTPC(One Time Programmable Memory Controller). Refer SAM-BA installation directory on how to write BCP to OTPC

Below steps can be used to program BCP to OTPC:

• sam-ba -p j-link -b sama7g5-ek -a bootconfig -c writecfg:bscr:EMULATION_DISABLED //Disable Emulation
• sam-ba -p j-link -b sama7g5-ek -a bootconfig -c readcfg:bscr // Read bscr and verify emulation is disabled
• sam-ba -p j-link -b sama7g5-ek -a bootconfig -c refreshcfg:otp //Refresh otp
• sam-ba -p j-link -b sama7g5-ek -a bootconfig -c writecfg:bcp-otp:DBGU,QSPI0_IOSET1 // Enable debug, QSPI0 as external NVM
• sam-ba -p j-link -b sama7g5-ek -a bootconfig -c readcfg:bcp-otp // Read bcp_otp and verify whether QSPI is set as external NVM

Debugging Application Project on MPLAB® X IDE

1. Open the project (sama7g54_ek_blink_led_qspi_xip/firmware/sama7g54_ek.X) in MPLAB® X IDE.
2. In the project properties, ensure SAMA7G54 is selected as the Device and for Connected Hardware Tool, select connected J-Link debugger with the board to program/debug the application.
3. Build the code. The harmony.bin file can be found in the /project_directory/dist/default/production/harmony.bin.
   Note: Before debugging ensure that harmony.bin file in the project directory is flashed in the QSPI offset.
4. Refer the SAM-BA Installation and Setup section for initial device setup and tool installation procedure.

   Use the below sam-ba commands to erase QSPI flash and program the application:

   • sam-ba -p j-link -b sama7g5-ek -a qspiflash -c erase //To erase entire QSPI flash
   • sam-ba -p j-link -b sama7g5-ek -a qspiflash -c erase:0x40000:0x20000 //Erase only 0x20000 bytes of data from the QSPI offset 0x40000
   • sam-ba -p j-link -b sama7g5-ek -a qspiflash -c write:harmony.bin:0x40000 //Program the application in the QSPI offset 0x40000
     Note: Do not flash boot.bin to QSPI memory to debug the application on MPLAB® X IDE.

     

5. Debug the code by clicking on the Debug button in MPLAB® X IDE tool bar and observe that the application is getting executed from QSPI flash memory.
6. Run the application by clicking the Run button in MPLAB® X IDE tool bar. A terminal emulation program running on the Host PC communicates with the SAMA7G54 Evaluation kit J-Link CDC. Ensure the terminal emulation program (Eg: PUTTY) is configured to the COM port and settings are:
   • Speed: 115200
   • Data: 8
   • Parity: None
   • Stop Bits: 1
7. The user will get the debug message on the serial console. Then, press the user button(sw1) and observe LED getting turned ON.

   

Running the Pre-built Harmony Application from QSPI Flash

The boot.bin and harmony.bin files can be found from the hex folder in the project directory. The pre-built application bin file and boot bin file can be programmed to QSPI flash using SAM-BA . Refer the above section: Flash the Application Project using SAM-BA for initial device setup and tool installation procedure.

Comments

This application demo builds and works out of box by following the instructions above in Running the Demo section. If the user needs to enhance/customize this application demo, should use the MPLAB Harmony v3 Software framework. Refer links below to setup and build the applications using MPLAB Harmony.

• How to Setup MPLAB Harmony v3 Software Development Framework
• How to Build an Application by Adding a New PLIB, Driver, or Middleware to an Existing MPLAB Harmony v3 Project
• How to Set up the Tools Required to Get Started with MPLAB® Harmony v3 and MCC
• Create a new MPLAB Harmony v3 project using MCC
• Click Here for more Harmony V3 applications