ADS7138: CRC calculation

Micha Klingler

Part Number: ADS7138

Hello,

I am using the ADS7138, for me is unclear how to use the CRC module.

As far as it is written in the documentation the CRC have to be appended to every byte read or write.

So when I configured the ADS7138 for the CRC mode I have to transmitt a read operation as following:

Host -> 7-Bit_Addr, R/W; Opcode; CRC; Addr; CRC;

Device -> Data; CRC; Data; CRC; .... Data; CRC;

The question is: Is Opcode and Addr also checked with a CRC? Or only the data bytes have its CRC?

How does it work for a write operation?

Host -> 7-Bit_Addr, R/W; Opcode; CRC; Addr; CRC; Data; CRC; Data; CRC; .... Data; CRC;

Regards

Micha Klingler

0 Cynthia over 2 years ago

Hello,

Yes, the op code and address both have to be included in the CRC code. Anything being transmitting will need to be included in the CRC code.

the CRC is needed after every byte (a group of eight binary digits or bits operated on as a unit)

Thus it would be

Host -> 7-Bit_Addr, R/W;CRC; Opcode; CRC; Addr; CRC; Data; CRC; Data; CRC; .... Data; CRC;

Regards

Cynthia

0 Micha Klingler over 2 years ago in reply to Cynthia

Hey Cynthia,

thanks for your answer, but it is not 100% correct.

Now I tried it out to see how it works. after sending the 7-Bit_Addr+R/W there is no CRC. After each other byte there is a CRC.

Thanks for your help.

Regards,

Micha

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