Speech have plosive sound point processed by C6713

Jiang pengfei,

PENGFEI JIANG said:

when we output the processed speech(in the first picture), we hear plosive sound point.

Either the result of the processing is incorrect or the wrong data is being written out. For the processing case, you will want to debug from the output buffer backwards. For the "wrong data" case you will want to compare the output data to the intended buffer data.

PENGFEI JIANG said:

we can see that there is some unnormal line in the second figure above. and the time interval is 32ms. The SAME as the frame length.

The most common cause of noise in output is cache coherency. I am not sure that this could be your problem, but it is the first thing to ask. Does your code use cache invalidate and writeback/flush commands to force coherency between the cache and buffer memory?

PENGFEI JIANG said:

I have the same problem when I copy data from one buffer to another in memory when using for loop, the problem disappeared when I substitute for loop by memcpy.

This is very unusual, since memcpy is essentially a pre-compiled for-loop. Could your code be taking too long to process the data?

PENGFEI JIANG said:

warning: creating output section "text" without a SECTIONS specification

The compiler-generated section name has a leading "." in ".text". The warning message above does not. You most likely have a typo in an assembly function, because it is rare to explicitly name the .text section in compiled code.

Regards,
RandyP

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Hi, Randy

RandyP said:

Either the result of the processing is incorrect or the wrong data is being written out. For the processing case, you will want to debug from the output buffer backwards. For the "wrong data" case you will want to compare the output data to the intended buffer data.

I don't think so that it is the "wrong data" case, because I have check the buffer many times. And I think my processing should have no problem, because all other charactors are the same with computer simulation except the periodical plosive sound point(we can see nothing in time domain waveform, but some vertical lines in frequency domain).

RanyP said:

The most common cause of noise in output is cache coherency. I am not sure that this could be your problem, but it is the first thing to ask. Does your code use cache invalidate and writeback/flush commands to force coherency between the cache and buffer memory?

I have no idea the concept of cache coherency now. I only allocate the cache in the link command file: IRAM. I think I didn't use cache anywhere else. Anyway, I think this may be the problem. Can you introduce me some documents that cover this issue, such as cache coherency, writeback/flush commands etc al?

RandyP said:

I have the same problem when I copy data from one buffer to another in memory when using for loop, the problem disappeared when I substitute for loop by memcpy.

This is very unusual, since memcpy is essentially a pre-compiled for-loop. Could your code be taking too long to process the data?

That may be happen. But not for this issure i am confronting.

RandyP said:

warning: creating output section "text" without a SECTIONS specification

The compiler-generated section name has a leading "." in ".text". The warning message above does not. You most likely have a typo in an assembly function, because it is rare to explicitly name the .text section in compiled code.

But I haven't write any assembly function by myself. And I haven't define any section in C by myself. Could that be the problem that IRAM(cache) have no enough space for .text section? There is no such warning when I run an "smaller" algorithm.

Regards,
Jiang Pengfei

PENGFEI JIANG said:

Can you introduce me some documents that cover this issue, such as cache coherency, writeback/flush commands etc al?

Please refer to the Two-level Internal Memory Reference Guide for your DSP. You can find this and all the related documentation in the TMS320C6713B Product Folder under Technical Documents.

PENGFEI JIANG said:

warning: creating output section "text" without a SECTIONS specification

You will need to figure out where this is coming from and either fix the typo or add a section specification. Start with the linker output .map file for help figuring out where this output section comes from.

Regards,
RandyP