I have some difficulties with CRC in AD7177.
In datashit (AD7177-2 datasheet page 42) it is said that an 8-bit polynomial is used.
But then, in the description, I see the polynomial x^8+x^2+x+1 with the highest power - 8.
Accordingly, the polynomial is no longer 8-bit, but 9.
And as a proof, the polynomial - 100000111 of 9-bit length is written below.
Tell me, please, is it a mistake in datashit or CRC really 9 bit?
And if there is an error, is there any information about the real value of a polynomial?