TMS320F28027: Chinese characters are garbled when using printf

Hello,

Yale Li 李耀先 said:

As the amount of programs increases

What exactly does this mean? Is this referring to the actual size of the code? I'm not sure why just Chinese characters would get impacted by this. Which terminal program are you using to see the strings from the serial port?

Thanks

ki

Hi Ki,

Thanks for your reply!

Ki said:

Is this referring to the actual size of the code?

Yes.

Ki said:

Which terminal program are you using to see the strings from the serial port?

SSCOM V5.13.1

Thanks & Regards

Yale Li

Thanks.

How is the target being run? Is it using CCS?

If you use a different terminal program, do you see the same results?

Thanks

ki

Hi Ki,

Ki said:

Is it using CCS?

Yes.

Ki said:

If you use a different terminal program, do you see the same results?

Yes, the issue still exist. 

Thanks & Regards

Yale Li

I have no explanation as for why the increase in code size would impact printf of chinese characters over serial. 

Are you able to try printf over JTAG to see if that is impacted also?

Hi Ki,

Sorry for this late reply.

Ki said:

Are you able to try printf over JTAG to see if that is impacted also?

No, it isn't impacted.

The customer found that an unit16 array[400] which he added cause the issue. And this warning appear : 

Description Resource Path Location Type #10247-D creating output section ".cio" without a SECTIONS specification F2803xHFSpwm3B C/C++ Problem

When he remove the array from the code, everything will be normal.

He doubt that heap&stack issue is the reason.

Thanks & Regards

Yale Li

Yale Li 李耀先 said:

No, it isn't impacted.

Thanks for confirming.

The issue appears specific to the printf over UART implementation. The compiler RTS library supports just printf over JTAG so I'm assuming some custom implementation was done to get this to work?

Hi Ki,

Thanks. Is there any materials of JTAG printf?

Thanks & Regards

Yale Li

The below article is a good primer on how printf works with CCS:

https://dev.ti.com/tirex/explore/node?node=A__AIwt8bIK1yTVvzbnfYL0gg__ccs_devtools__FUz-xrs__LATEST

The default transport for printf in CCS is JTAG. Anything else usually requires a custom port.