CRC Algorithms Basics

[FreshmanNewbie]

I am reading about CRC algorithms. And have a few basic doubts

Referred Link - https://www.st.com/resource/en/application_note/dm00068118-using-the-crc-peripheral-in-the-stm32-family-stmicroelectronics.pdf

Suppose, I have a Microcontroller and another receiving device.

I have 3 questions :

1. If the receiving device is not capable for supporting CRC, How does the MCU Verify the integrity of the data that was sent to the receiving device? Does the MCU Take back the sent data once again and check for CRC? Or how does it happen?

2. Is checksum done for all data transactions or only specific data transactions? Is it a mandatory thing to do for each data transfer?

3. Last question, Is checksum only done for data values or address values too?

 

[wwfeldman]

are you building it, or are you dealing with an existing design?

I have 3 questions :

1. If the receiving device is not capable for supporting CRC, How does the MCU Verify the integrity of the data that was sent to the receiving device? Does the MCU Take back the sent data once again and check for CRC? Or how does it happen?

2. Is checksum done for all data transactions or only specific data transactions? Is it a mandatory thing to do for each data transfer?

3. Last question, Is checksum only done for data values or address values too?

1) if you're building it, make sure the receiver (which is likely another MCU) will handle CRC
if you're dealing with an existing device, what did it do?

2 & 3) if you're building it, you get to decide - are you checking the transmission for correct reception, or are you checking something else?
if the check is for correct reception, then all of the information transmitted is data and should be checked.
after that, you can separate data from address

 

[FvM]

The linked application note is specifically discussing CRC usage to verify code integrity in safety related applications. You have apparently a different application in mind, without explicitly telling what it is.

If a receiving device isn't able to calculate a CRC (any programmable device can at least at moderate speed), how should it be able to echo the date to the CPU?

What is the imagined communication that involves data and address values?