i.MX RT Crossover MCUs中的主题 Specify a variable to be in a specific RAM region for mimxrt1064

Specify a variable to be in a specific RAM region for mimxrt1064

ruohaig — Wed, 08 Apr 2020 16:15:11 GMT

Hi,

I was trying to manipulate with evkmimxrt1064_dev_video_virtual_camera_bm SDK example.

Does anyone know why a variable declared non-cacheable( should be in NCACHE_REGION, part of SDRAM) found in another memory area (DTCM, part of flexRAM) after compile, which causes memory overflow?

Does anyone know how to specify a variable to be in a specific RAM region for mimxrt1064?

Thx

Re: Specify a variable to be in a specific RAM region for mimxrt1064

kerryzhou — Thu, 09 Apr 2020 12:38:55 GMT

Hi Ruohai Ge,

Do you evkmimxrt1064_dev_video_virtual_camera_bm SDK code non-cacheable variable located in the wrong place? Could you tell me more details about it, which variable?

About how to specify a variable to be in a specific RAM region for mimxrt1064, please tell me your IDE, then I can help you to find the detail method.

Wish it helps you!.

If you still have question about it, please kindly let me know.

Kerry

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Re: Specify a variable to be in a specific RAM region for mimxrt1064

ruohaig — Thu, 09 Apr 2020 17:41:22 GMT

Hi,

I am not quite sure about that. "AT_NONCACHEABLE_SECTION_ALIGN(
static uint16_t s_frameBuffer[APP_FRAME_BUFFER_COUNT][DEMO_PANEL_HEIGHT][DEMO_PANEL_WIDTH],
DEMO_FRAME_BUFFER_ALIGN);", I declared such as variable. I thought this should be in the NCACHE_REGION, but instead, it is in the SRAM_DTC ("RAM2" of this project)

I am using mcuxpresso.

Thank you very much.

Re: Specify a variable to be in a specific RAM region for mimxrt1064

kerryzhou — Sun, 12 Apr 2020 08:36:57 GMT

Hello Ruohai Ge,

Please open the MCUXPresso IDE install path, the related user guider:

C:\nxp\MCUXpressoIDE_11.1.0_3209\MCUXpresso_IDE_User_Guide.pdf

chapter 17.13 Placement of specific code/data Items

You will find the detail method.

You can define the noncache SDRAM area, then use this code:

__NOINIT(RAMn) char noinit_buffer[128];

RAMn is the noncacheable SDRAM area.

Please try it.

If you still have questions about it, please kindly let me know.

Kerry

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