A way to make emWin use an external SDRAM instead of internal RAM

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    • A way to make emWin use an external SDRAM instead of internal RAM

      Hi,

      I'm using a library version of emWin, but I would like to ask if there is a way/option to make emWin use an external SDRAM instead of internal RAM.
      For the application part, I think I can use compiler/linker options (#pragma or something).

      Thanks in advance.

      Best Regards,
      Rowel

    • Hi,

      You have to link the "GUI-memory" into the SDRAM. How this is done depends our your linker.


      emWin will allocate memory only from the block set with GUI_ALLOC_AssignMemory().


      Here is an example from a GUIConf.c which does it.


      C Source Code

      1. #include "GUI.h"
      3. /*********************************************************************
      4. *
      5. * Defines
      6. *
      7. **********************************************************************
      8. */
      9. //
      10. // Define the available number of bytes available for the GUI
      11. //
      12. #define GUI_NUMBYTES (1024 * 1024 * 4)
      14. #if (defined __ICCARM__) // IAR
      15. static __no_init U32 aMemory[GUI_NUMBYTES / 4] @ "GUI_RAM";
      16. #elif (defined __SES_ARM) // SES
      17. static U32 aMemory[GUI_NUMBYTES / 4] __attribute__ ((section (".GUI_RAM")));
      18. #else
      19. static U32 aMemory[GUI_NUMBYTES / 4];
      20. #endif
      22. /*********************************************************************
      23. *
      24. * Static code
      25. *
      26. **********************************************************************
      27. */
      29. /*********************************************************************
      30. *
      31. * Public code
      32. *
      33. **********************************************************************
      34. */
      35. /*********************************************************************
      36. *
      37. * GUI_X_Config
      38. *
      39. * Purpose:
      40. * Called during the initialization process in order to set up the
      41. * available memory for the GUI.
      42. */
      43. void GUI_X_Config(void) {
      44. //
      45. // Assign memory to emWin
      46. //
      47. GUI_ALLOC_AssignMemory(aMemory, GUI_NUMBYTES);
      48. }
      Display All

      If you are using the GUIDRV_Lin driver you might also want to link the frame buffer to the external memory. This is most likely done the same way as with the "GUI-memory".

      Regards
      Sven
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