Compiler/TMS320F28069: Data Page Pointer (DP) is not updated.

Ruben de Schipper

Tool/software: TI C/C++ Compiler

I have data that is being shared between the CPU and CLA. The struct starts at page 0x54 and ends on 0x55. (both in CPU and CLA shared RAM).

When I write to a variable in the struct that lies on page 0x55 and after that to one that lies on page 0x54 that data page pointer stays at 0x55 and the wrong memory location is updated.

I am attaching some test code that demonstrates the affect.

I used the latest compiler (i.e. ti_cgt_c2000_18.9.0.STS)

over 7 years ago

0 Sudhakar Singh47 over 7 years ago

TI__Intellectual 860 points

Hello,

Concerned experts have been notified of this query.

Note that it is Thanksgiving week in US and most of the TI engineers are away.

Please expect a delayed response, surely by early next week.

Regards,

Sudhakar

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0 Whitney Dewey over 7 years ago in reply to Sudhakar Singh47

TI__Guru 54725 points

How are you observing this issue? Are you stepping through the code and watching the DP register in the Registers view in CCS? Does the code in the disassembly window appear to be correct? Do you mind sharing a screen capture?

Thanks,
Whitney

0 Ruben de Schipper over 7 years ago in reply to Whitney Dewey

Prodigy 80 points

screenshots.zip

Hi,

In the attached file, you will find screenshots that show the issue:

The screens capture 6 assembly steps through the test code. Screen 6 shows that the value (i.e. 100.0) that should have been written to address 0x153E is instead written to address 0x157E.

Address 0x153E is on data page 0x54, with an offset of 0x3E and address 0x157E is on data page 0x55 with an offset of 0x3E.

In my first message, I attached the source code for this test program.

Thanks in advance for your help.

Best regards,

Ruben

0 Ruben de Schipper over 7 years ago in reply to Ruben de Schipper

Prodigy 80 points

Hi,
Have you been able to reproduce my issue?
I am curious about the progress :)

Thanks in advance for any help.

/Ruben

0 Whitney Dewey over 7 years ago in reply to Ruben de Schipper

TI__Guru 54725 points

Thanks for your patience. I'm seeing the same issue--I agree that it appears an update to the DP is missing. I'll forward your post to the compiler team and see what they think.

Whitney

0 George Mock over 7 years ago in reply to Whitney Dewey

TI__Guru**** 253230 points

Unfortunately, this is a known issue. The workaround is, when defining variables that are shared between CLA and C28x, define them in the C28x code, not the CLA code.

This forum thread has a longer discussion of the issue.

The entry CODEGEN-1407 is filed in the SDOWP system. It requests that a diagnostic be issued when the user makes the error of defining a variable in CLA code, then reading it from the C28x code. Right now, it is not exposed publicly. I'll get that fixed, and then you can track it with the SDOWP link below in my signature.

Thanks and regards,

-George

0 George Mock over 7 years ago in reply to George Mock

TI__Guru**** 253230 points

The entry CODEGEN-1407 is in the SDOWP system, but you have to look it up with the original ID SDSCM00052289. I'm sorry I overlooked that. For convenience, this is a direct link.

Thanks and regards,

-George

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Compiler/TMS320F28069: Data Page Pointer (DP) is not updated.