CCS/TMS320F28335: Locating Code & Data on FLASH and RAM

Abhinand Dhanakshirur

Prodigy 195 points

Part Number: TMS320F28335

Tool/software: Code Composer Studio

I am developing application in MATLAB/Simulink environment and integrate generated code onto F28335 device.

I am facing problem with location code and data onto FLASH and RAM.

My previous software had following code and data sections.

.text = 22759

.cint = 2351

.econst = 538

.ebss = 2918

I located these sections onto FLASHA(.text, .cint, .econst) and RAML4(.ebss).

After i have done changes to some application files, code and data looks like this:

.text = 23109

.cint = 10224

.econst = 538

.ebss = 10726

Now using linker command file i located .text, .econst sections on FLASHA and .cint on FLASHB.

RAM on device is L0-L7(4k x 16 each) & i can only use L4-L7. In order to fit 10726 bytes into RAM, i combined RAML4 RAML5 RAML6 with name "RAML4" as one section as follows in linker command file:

RAML4 : origin = 0x00C000, length = 0x003000

And then located .ebss on RAML4

My question:

1) Can sections of (.text, .cint, .econst) be located on different FLASH blocks? As they were located on the same block earlier.

2) Is if this way of combing the RAM is allowed and does this have any implication in run time performance?

Thank you!

over 5 years ago

0 Veena Kamath over 5 years ago

TI__Mastermind 32655 points

Hi Abhinand,

1) Can sections of (.text, .cint, .econst) be located on different FLASH blocks? As they were located on the same block earlier.

Yes, you can use any Flash blocks for these sections. You can even use multiple Flash blocks for one section (As mentioned in the answer below)

2) Is if this way of combing the RAM is allowed and does this have any implication in run time performance?

You can map a section to multiple RAM blocks as shown below:

.ebss : >> RAMLS5 | RAMLS6

Or you can combine the memory blocks as a single block and use that for the sections as shown below:

RAMLS01 : origin = 0x008000, length = 0x001000

.ebss : > RAMLS01

Regards,

Veena

0 Ozino Odharo over 5 years ago in reply to Veena Kamath

TI__Mastermind 21600 points

Abinand,

Please also refer to the following wikipage for more information on linking. https://processors.wiki.ti.com/index.php/C28x_Compiler_-_Understanding_Linking

Regards,

Ozino

0 Abhinand Dhanakshirur over 5 years ago in reply to Veena Kamath

Prodigy 195 points

Hi Veena,

Thanks for your response.

Option 2 works for me that is:

Or you can combine the memory blocks as a single block and use that for the sections as shown below:

RAMLS01 : origin = 0x008000, length = 0x001000

But Option 1 does not work for me.

".ebss : >> RAMLS5 | RAMLS6 "

0 Veena Kamath over 5 years ago in reply to Abhinand Dhanakshirur

TI__Mastermind 32655 points

Hi Abhinand,

Sorry for the delayed response.

When you do the following, the linker will try to split the ebss section into 2 subsections and place one in LS5 and one LS6.

".ebss : >> RAMLS5 | RAMLS6 "

For some reason, if linker is unable to split the section or if the subsection size is more than the size of the memory region, this solution will not work.

Usually linker tries to keep the ebss section in one file as a single section.

Regards,

Veena

0 Abhinand Dhanakshirur over 5 years ago in reply to Veena Kamath

Prodigy 195 points

Hi Veena,

Thanks for your response. That helps.

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CCS/TMS320F28335: Locating Code & Data on FLASH and RAM