CCS/TMS320F28069: Char Array Memory Allocation in 16-bit Memory

rjb

Part Number: TMS320F28069

Tool/software: Code Composer Studio

Hello,

I am working on TMS320F28069 C28x.

I have created an array of char as can be seen from the image above for 8-bits datatype it takes 16-bits memory and higher byte is empty.

Any suggestions on how to pack it in memory -> 8 bits side by side. Is there any way of telling compiler to do that ?

Thanks,

Rahul

over 5 years ago

0 Yanming Luo over 5 years ago

TI__Guru** 112440 points

You might have a look at the chapter of C compiler user's guide as the following link. The data type, char or signed char is 16 bits size for C2000.
www.ti.com/.../spru514r.pdf

I am working to find the compiler expert to help you. This may take some time to reach the right person depending on availability. Please expect an update over the weekend. I appreciate your patience.

0 rjb over 5 years ago in reply to Yanming Luo

Intellectual 470 points

Thanks for getting back on this Yanming,
I am waiting and eager to find out optimization, I can surely do this by adding few lines of code to do that. But, I want to know if there is any intrinsic compiler option for this.

I also used __attribute__((__packed__)) for structure allocation of two characters (not for char array) it didn't pack two chars together, still had two different locations.

Thanks,
Rahul

0 George Mock over 5 years ago in reply to rjb

TI__Guru**** 241235 points

The C28x compiler does not support a built-in type that is 8-bits wide. To understand how you can do 8-bit wide operations from C code, please see the article Byte Accesses with the C28x CPU.

Thanks and regards,

-George

0 rjb over 5 years ago in reply to George Mock

Intellectual 470 points

That's helpful George thanks.

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CCS/TMS320F28069: Char Array Memory Allocation in 16-bit Memory