TMS320F28027: IQmath issue

Cherry Zhou

Part Number: TMS320F28027
Other Parts Discussed in Thread: TMS320F28021,

Hi team,

Here's an issue from the customer may need your help:

iqtmp =_IQ(spwmiqvar.spwm_cnt)+_IQ(SIN_B);

spwmiqvar.sinvale =_IQsin(spwmiqvar.sina);

spwmiqvar.sinb =_IQmpy(spwmiqvar.M_FACTOR,spwmiqvar.sinvale);

spwm_value=1000+1000*_IQtoF(spwmiqvar.sinb);

These IQ operations cause printf to have no output and the while function of main function is not executed, and the program is very slow. However, if comment out any of the two statements above, it can be executed properly. Is it because IQ execution is time consuming and causes an interrupt to overflow? Spwmiqvar.spwm_cnt is the uint16_t type data, other are decimal numbers.

Could you help check this case? Thanks.

Best Regards,

Cherry

over 3 years ago

0 Shanty over 3 years ago

TI__Expert 5410 points

Hi,

Can you share where the printf is called and what exactly the ISR is doing? These four statements should take <90 clock cycles. Is this window too large for the rest of the program?

-Shantanu

0 Cherry Zhou over 3 years ago in reply to Shanty

TI__Mastermind 22235 points

Hi Shantanu,

Thanks for your help.

Sure, Printf is in the while loop, the ISR is used to calculate the value of SPWM.

Thanks and regards,

Cherry

0 Cherry Zhou over 3 years ago in reply to Cherry Zhou

TI__Mastermind 22235 points

Hi,

Quick update:

The code with IQ issues is as follows:

https://e2echina.ti.com/cfs-file/__key/communityserver-discussions-components-files/56/28027IQTest2.rar

Also here's an additional question: using the Burner Downloader, it is found that the download speed is slow, with the following error:

C28xx: Error occurred during flash operation: Timed out waiting for target to halt while executing FlashAPIInterface2802xV2_00.out

Thanks and regards,

Cherry

0 Shanty over 3 years ago in reply to Cherry Zhou

TI__Expert 5410 points

Will check and get back to you asap when I get the bandwidth.

0 Cherry Zhou over 3 years ago in reply to Shanty

TI__Mastermind 22235 points

Hi,

Thanks and expect the results.

Regards,

Cherry

0 Cherry Zhou over 3 years ago in reply to Cherry Zhou

TI__Mastermind 22235 points

Hi Shantanu,

May I know is there anything new?

Thanks and regards,

Cherry

0 Cherry Zhou over 3 years ago in reply to Cherry Zhou

TI__Mastermind 22235 points

Hi,

May I know where can find the specific application example of TMS320F28021 and TMS320F28027? And is there any update regarding IQ data?

Thanks and regards,

Cherry

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TMS320F28027: IQmath issue