TMS320F28069: CLA memory to cpu issue

Hi,

Where is CLA_Freq being stored? It is a local variable, but has the memory location of it changed in the two implementations?

It looks like the CLA has access to the CLA_Test and the CLA_estdata struct, so I am not sure at the moment why it would not be reading the counter and writing it to CLA_Freq.

Can you step through that code with the debugger and see what is being read into registers and stored to the CLA_Freq memory location?

sal

There are no changes between the two tests then there except which variable is stored in CLA_FREQ. and in the debug window I can see the cla fill the variables correctly.

So what is the difference between the cla and cpu?  The only thing I could find is memory bus width. So I start re-arranging  the struct and made all the variables 32 bit width. After that it  starts works.

So I thing you got there an issue there in the compiler. Only the last time I reported a problem. The best TI can do is suggesting to manual modify the asm code to get it working. So that is useless.

So is there a compiler directive to tell the cpu the struct is 32 bit aligned?

Thanks!

Hi,

Because the structure is defined by the C28x, the elements of the structure are the size defined by the C28x compiler.  Enumerated types and integers will have a different size on the C28x than the CLA. On the C28x, they are 16-bits. On the CLA, they are 32-bits.

See Section 10.2 of the  This is the Optimizing C/C++ Compiler User's Guide

Because of the above, it appears the CLA compiler was grabbing memory which was initialized to zero. Perhaps it was reading counter from memory which was past the declaration of the structure elements. Can you confirm this, please?

Regards,

sal

If you use data types which define the memory size, I think it would work even if you used 16-bits types. You can try declaring the structure using standard data types like: int16_t, uint16_t, int32_t, float32_t, etc.

Hope this helps,
sal

Sal Pezzino said:

If you use data types which define the memory size, I think it would work even if you used 16-bits types. You can try declaring the structure using standard data types like: int16_t, uint16_t, int32_t, float32_t, etc.

Hope this helps,
sal

stdint.h

    typedef          int    int16_t;
    typedef unsigned int   uint16_t;
    typedef          long   int32_t;
    typedef unsigned long  uint32_t;

If you didn't know that .Please forward my problem  to someone more senior.

If I change the order of the variable of the struct in the CLA. I can change the result of the output. I think that is an issue. I have a lot of issues reading data back from CLA so I spend a couple of days debugging it. There is an issue with 32 bit vs 16 bit data width in data structures in the compiler.  It is easy to reproduce.

Bonus: also check the sizeof a enum for cpu and cla. If you set a value at the enum at the cpu. The CLA can read something else. Because the cpu can't set the higher 16 bit word enum of the CLA data field. at Init there can be a random value. And the cpu can't change it.