This is the documentation for the latest (main) development branch of mcuxpresso sdk. If you are looking for the documentation of previous releases, use the drop-down menu on the left and select the desired version.

Hardware requirements

  • Micro USB cable

  • RD-RW61X-BGA board

  • Personal Computer

Board settings

Prepare the Demo

  1. Connect a micro USB cable between the PC host and the MCU-Link USB port (J7) on the board

  2. Open a serial terminal with the following settings:

    • 115200 baud rate

    • 8 data bits

    • No parity

    • One stop bit

    • No flow control

  3. Download the program to the target board.

  4. Launch the debugger in your IDE to begin running the demo.

Running the demo

When the example runs successfully, you can see the similar information from the terminal as below.

FLEXSPI dma example started!
Vendor ID: 0xc2
Erasing Serial NOR over FlexSPI...
Erase data - successfully. 
Program data - successfully.

NOTE: In this project, after starting DMA, the project (function flexspi_nor_flash_program in flexspi_nor_flash_ops.c) uses a while loop to check a variable (g_completionFlag) to get the DMA transfer done status. With RW610-RW612, each SRAM region access priority is fixed as:

  • CM33 C-AHB is the highest priority

  • CM33 S-AHB is the next priority

  • The AHB matrix is the lowest priority When the function flexspi_nor_flash_program code, variable g_completionFlag, and the DMA accesssed buffer s_nor_program_buffer are in the same SRAM region, CM33 core while loop accesses the SRAM region frequently, so DMA can’t get data in time, and results to FlexSPI timeout. The solution is place the CM33 accessed function/variable and DMA accessed variable to different SRAM region.