Mailbox issue (received data is not the same with the data sent)

Xuedong

Prodigy 160 points

Hi,

I would like to get guidance about what are in the 4 mailbox areas.

In the link.map file, I observed

........................................

000f3fd8   _MBX_ul_frame
000f3fe8   _MBX_ul_frame$data
000f4008   _MBX_ul_frame$free
000f4044   _MBX_dsp2ppc

...................................

000f4310 _MBX_ul_frame$queElems
000f4478 test$stack

......................................

So I can figure out that there are 4 areas for the mailbox (MBX_ul_frame):

MBX_ul_frame: length 0x10,

MBX_ul_frame$data: length 0x20,

MBX_ul_frame$free: length 0x3C,

MBX_ul_frame$queElems: length 0x168

Can anyone guide me what are in the 4 areas? In other words, if I have the data from the 4 areas, how can I parse them?

Actually, I am debugging a problem of mailbox. The received data (MBX_pend) is not the same with the data sent (MBX_post). My understanding for mailbox mechanism is that when running MBX_post(), the data will be copied from the sending local memory to a global area. And when running MBX_pend(), the data will be copied to the receiving local memory from the global area. It seems to me that something like overwriting happened between after MBX_post() and before MBX_pend(), so that the global area is overwritten before MBX_pend(). This results in the wrong received data.

If we know where the "global area" is, we may be able to find out who overwrites it by using the conditional breakpoint. I guess that the address of the "global area" is indicated in one of the 4 areas listed above. If anyone can guide me how to parse the data in the 4 areas, that would be very helpful.

Also has any expert experienced such problem before? Any idea what could be the cause of the problem?

Many thanks in advance.

Xuedong

over 16 years ago

0 TommyG over 16 years ago

TI__Genius 13045 points

Moved to Code Composer Studio thread to get better exposure.

0 Mariana over 16 years ago

TI__Mastermind 24340 points

Hi Xuedong,

For data corruption cases like that, I have some suggestions:

- If you are creating the MBX dynamically, make sure that you are not using local variables, so the data can be corrupted.

- Make sure you are using the handle to the same MBX.

- Make sure that you are including the header file that is created by the tfc file: youprojectnamecfg.h.

Hope this helps.

0 Stephen English40592 over 15 years ago

Prodigy 110 points

Dear Xuedong,

I am also experiencing data corruption when passing data through a mailbox. Did you find out what was causing your error?

Many thanks,

Steve English

0 Aruru Praveen over 12 years ago

Prodigy 170 points

Hi Xuedong ,

Did you get the answer for this above question?

Any idea what each identifier refers to?

I am getting a problem of mailbox full, so i need to parse the data in these variables and get the messages which are posted, Can you tell me what each variable refers and how to get the fileds in that?

Thanks & Regards

Praveen Aruru

0 Karl Wechsler over 12 years ago in reply to Aruru Praveen

TI__Mastermind 20805 points

Please open a new thread with specific information including which device and version of SYS/BIOS or DSP/BIOS you are using? This thread is closed and there's not enough information in your request to give any suggestions.

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Mailbox issue (received data is not the same with the data sent)