Signature Unit in iMX8QM

[MHassan1]

Hello,

I am working on Core m4 in Imx8qm , and I am supposed to configure Signature unit to calculate CRC over display rendering from m4. 

But in oreder to do so , I need to provide this API 

DPU_SetSignatureWindowRefCrc(DPU_BASE, DISPLAY_INDEX, 0, redCRC, greenCRC, blueCRC) With Reference redCRC, greenCRC, blueCRC in order to be checked against what calculated from Signature unit.

So My question is that, Is there a component or a mechanism describe how to calculate CRC the same way signature unit do, because other than that, Signature unit will always failed in that comparison. 

And if not, So how Signature unit supposed to work in that way, As it is not logical to set the reference values with the same values that calculated from Signature Unit itself like what implemented in SDK example 

boards/mekmimx8qm/driver_examples/dpu/signature/cm4_core1/dpu_signature.c

Thank you,

[Juan-Rodarte]

Hi Mahmoud,

Which SDK are you using?

[MHassan1]

Hi Juan,

Thank you for your feedback.

I am using  SDK_2_5_2_MIMX8QM6xxxFF  as it is the latest SDK with Signature unit example.

Thank you,

[Juan-Rodarte]

Hi,

I share a link for more information.
https://mcuxpresso.nxp.com/api_doc/dev/1694/a00014.html#ga77322b7b303eb2ed8d55ad4032ea10b1

Regards.

[fmonte]

This does not answer the question. Your link (that is just a doxigen of fsl_dpu.h) does not specifie the CRC type.

[MHassan1]

Exactly, This actually has nothing to do with the CRC type for signature unit. And for me without knowing this point, Signature unit seems to be very useless for dynamic graphics.