Have issues for use the PSRAM instead of QSPI_FLASH on mxrt595

[Wayne2]

Hi NXP team:

I want to use the PSRAM instead of QSPI_FLASH

1.Add psram in the MCU settings, location from 0x28000000, the size is 4MB(it has 8MB PSRAM in the sheet)

2."Global data placement" we set use the RAM_00(PSRAM)

3.Build and Debug

Result:

It can't run my task, and has assert in the configASSERT( uxSchedulerSuspended); 

Can you give me some advice how to solve it?

Thanks

[Omar_Anguiano]

Hello
Hope you are well.

It is important that the PSRAM is initialized by the time the data is placed in the PSRAM.
Just to confirm; Does this issue happens when you place global data in the internal SRAM?
It will be helpful to place specific code/data by using __DATA(RAM3) variable

If you have more questions do not hesitate to ask me.
Best regards,
Omar

[Wayne2]

Hello 

I added these two functions in my main

BOARD_InitPsRamPins();

BOARD_InitPsRam();

And it's aslo ok when I put my own heap to the psram(RAM_00).

add "uint8_t ucHeap[ configTOTAL_HEAP_SIZE ] __attribute__ ( (section( ".my_heap" ) ) ); " in my code.

set the ".my_heap" to the RAM_00, it can run successfully.

When I used the link application to RAM, it aslo can run successfully.

Could you explain "It will be helpful to place specific code/data by using __DATA(RAM3) variable" more specific?

Thanks

[Omar_Anguiano]

We can use the prefix to place specific code/data in a specific location. e.g.

#include<cr_section_macros.h>
__DATA(RAM3) chardata_buffer[1024];

It will be helpful to check that cache is disabled on the FlexSPI interface connected to PSRAM.