Dynamic ramp saturation issue towards zero

[LEGR]

I am implementing a DRamp functionality with RTCESL version 4.62, where I have issues with the saturation when the absolute ramp value is falling.

According to the documentation, the stop flag causes the ramp value to turn back towards the given instance, but this does not work in the implementation I did.

I tried both. A ramp with positive request and a ramp with negative request.

Is there a known issue or any other reason, the ramp does not respect the stop flag?

[Harry_Zhang]

Hi @LEGR 

May i ask which chip you are using?

BR

Harry

[LEGR]

Hi @Harry_Zhang,

we are running with LPC5534JBD100.

Best regards
Lennart

[Harry_Zhang]

Hi @LEGR 

I tried RTCESL 4.8.1 for CM33F and have not found the issue you mentioned. Please try use latest RTCESL library.

Could you send me the code so I can help you analysis.

BR

Harry

[LEGR]

Hi @Harry_Zhang ,

unfortunately, I can only find the version 4.7.1 for CM33F.

Real Time Control Embedded Software Motor Control and Power Conversion Libraries | NXP Semiconductor...

Where can I find the version 4.8.1?
Right now, we are using 4.6.3 and for 4.7.1 the only change is recompiling the KEIL libraries with a new compiler.

I attached the code I used for testing the function.

Best regards
Lennart

[Harry_Zhang]

Hi @LEGR 

May i ask what compiler you are using?

BR

Harry

[LEGR]

Hi @Harry_Zhang ,

I am wondering that you need the information, when you can recreate the issue. I already spent quite some time, that you really take a look at the described behavior.

The compiler I am using is:
arm-none-eabi-gcc (GNU Arm Embedded Toolchain 10.3-2021.07) 10.3.1 20210621 (release)

BR

Lennart

[Harry_Zhang]

Hi @LEGR 

Is it enough for you to fix only GFLIB_DRamp_FLT and rebuild library or also GFLIB_DRamp_F16, GFLIB_DRamp_F32 functions are used in your application?

In case all 3 DRamps need to be fixed We would estimate to send rebuild lib in next week.

BR

Harry

[LEGR]

Hi @Harry_Zhang ,

we are only running the GFLIB_DRamp_F16 and GFLIB_DRamp_F32, since our software still bases on an older controller, where no floating-point unit was supported.

BR

Lennart

[Harry_Zhang]

Hi @LEGR 

We have reproduced this issue and fix it.

The next release will wait for some time.

So we want to recompile the library for you.

BR

Harry

[Harry_Zhang]

Hi @LEGR 

The latest RTCESL will not be published alone on NXP website.

You can clone it from GIThub (nxp-mcuxpresso/rtcesl: NXP Real Time Control Embedded Software Library)

BR

Harry

[LEGR]

Hi @Harry_Zhang ,

I tried the ramp using RTCESL 4.8.1 for CM33F, but the result is the same.

The saturation only works while the absolute ramp value increases.

BR
Lennart

[Harry_Zhang]

Hi @LEGR 

We can reproduce this issue.

We are currently investigating this issue internally, and if there is any progress, I will inform you promptly. Thank you for your information.

BR

Harry