How to initializing variable placed in SDRAM

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

How to initializing variable placed in SDRAM

1,148 Views
jake111
Contributor I

There is a SDRAM on my board,and the SDK example "semc cm7" works which write serveral bytes then read and compare.

I want to place some big arrays to SDRAM,and set configuration in MCUXPresso IDE:

1.Add "Memory details" which region is RAM8

2.Add "Extra linker script input sections" in "Managed Linker Script"

Then declare a variable:

__DATA(RAM8) char test[8] = {1,2,3,4,5,6,7,8};

But the program fails to run to main.It seems the initializing code should be placed before "copy data" code.Then I put the SDRAM initializing code(including Pin,Clock,MPU and SEMC config) after "System_init()"(before copy data code),the read&write test passes.But the variable "test" is not initilalized as {1,2,3,4,5,6,7,8}.

How Can I copy the initializing data to SDRAM just like copying data to SRAM?And Why the program fails to run in the case of I initialize SDRAM after "copy data" code since it is actually not successfully copied to SDRAM?

 

And I've noted that .SCP file may relate to initialize the SDRAM.What is it used for?Do you have any document?

0 Kudos
Reply
1 Reply

1,081 Views
jake111
Contributor I

Anybody?

0 Kudos
Reply