Compiler/TMS320F28377D: How to put large array in Global Shared Ram

David,

You can combine the section, and make a larger section for your need.

Please refer to Linker Command Primer page and check the splitting the section.

software-dl.ti.com/.../sdto_cgt_Linker-Command-File-Primer.html

Thanks Santosh,

After a day going through that reference and the assembler documentation, not much closer (although I keep learning more about linking) So I am trying to figure out the syntax for the DATA_SECTION pragma (is it simply a name that gets translated into the object code as a section?) and then how to translate that section name to an output memory section. What is the input section name? is it the same as what is given in the DATA_SECTION pragma? Am I allowed to create any memory section output name (that is not reserved) and does it have to be a .xxxxx syntax?

      Thanks again

David,

Compiler users guide also explains the linker command file.

David Peter1 said:

What is the input section name? is it the same as what is given in the DATA_SECTION pragma?

Yes, You create a section with a given name, and then you place the section in your memory_section and then place your variable in this section using DATA_SECTION.

David Peter1 said:

Am I allowed to create any memory section output name (that is not reserved) and does it have to be a .xxxxx syntax?

Yes, you can give the section name whatever you like. Do not use any section name which is already used by compiler. Refer to compiler documentation

Thanks again Santosh,

I have been using the Compiler users guide as well, it is not real specific on the actual argument syntax for the DATA_SECTION pragma, so I appreciate your response.

I did run into a few problems. One is that in creating a new .cmd file that I put in the project directory, had problems with a linked .cmd file. It took me some time to figure out that CCS looks in the project files first and had duplicate .cmd files. The linked .cmd file was from the original project setup, and when it was deleted (along with the same file in the build config), then it worked.

The other problem is that it appears that the linker does not like to cross memory boundaries with a single entity, such as my arrays. This limits the array size to the size of the memory section. This is workable for my application but it would be nice if larger arrays using multiple memory spaces was doable.So unless there is a way to do that then I am good with this solution.

Here is the snippet from the C code:

// Put Data in Global Shared RAM, DATA_ARRAY is assigned to RAMGSx in Linker .cmd file
#pragma DATA_SECTION (Data1_Int, "DATA_ARRAY_1")
#pragma DATA_SECTION (Data1_Dat, "DATA_ARRAY_2")
#pragma DATA_SECTION (Data2_Int, "DATA_ARRAY_1")
#pragma DATA_SECTION (Data2_Dat, "DATA_ARRAY_3")
#pragma DATA_SECTION (Data3_Int, "DATA_ARRAY_1")
#pragma DATA_SECTION (Data3_Dat, "DATA_ARRAY_4")
#pragma DATA_SECTION (Data4_Int, "DATA_ARRAY_1")
#pragma DATA_SECTION (Data4_Dat, "DATA_ARRAY_5")

Uint32  Data1_Int   [Array_Depth1][2];
float   Data1_Dat   [Array_Depth1][Array_Width1];
Uint32  Data2_Int   [Array_Depth2][2];
float   Data2_Dat   [Array_Depth2][Array_Width2];
Uint32  Data3_Int   [Array_Depth3][2];
float   Data3_Dat   [Array_Depth3][Array_Width3];
Uint32  Data4_Int   [Array_Depth4];
float   Data4_Dat   [Array_Depth4][Array_Width4];

And here is the snippet from the linker .cmd file in the Sections

   DATA_ARRAY_1        :    > RAMGS2 ,  PAGE = 1
   DATA_ARRAY_2        :    > RAMGS3 ,  PAGE = 1
   DATA_ARRAY_3        :    > RAMGS4 ,  PAGE = 1
   DATA_ARRAY_4        :    > RAMGS5 ,  PAGE = 1
   DATA_ARRAY_5        :    > RAMGS6 ,  PAGE = 1

Hi David,

David Peter1 said:

I did run into a few problems. One is that in creating a new .cmd file that I put in the project directory, had problems with a linked .cmd file. It took me some time to figure out that CCS looks in the project files first and had duplicate .cmd files. The linked .cmd file was from the original project setup, and when it was deleted (along with the same file in the build config), then it worked.

Yes, all the files in the folder are included. So if you have more than one .cmd file in that folder, then you can "exclude the file from compile" by right-clicking on the file.

David Peter1 said:

The other problem is that it appears that the linker does not like to cross memory boundaries with a single entity, such as my arrays. This limits the array size to the size of the memory section. This is workable for my application but it would be nice if larger arrays using multiple memory spaces was doable.So unless there is a way to do that then I am good with this solution.

Regarding this, your implementation looks good. If you want to have it split across multiple sections, then you can try something like below (not sure if you tried already):

DATA_ARRAY_1        :    >>  RAMGS2 |  RAMGS3,  PAGE = 1