AD4112BCPZ datasheet(39/58 Pages) AD

39 / 58 page

Data Sheet

AD4112

Rev. A | Page 39 of 58

CRC CALCULATION

Polynomial

The checksum, which is eight bits wide, is generated using the

following polynomial:

x8 + x2 + x + 1

To generate the checksum, the data is left shifted by eight bits to

create a number ending in eight Logic 0s. The polynomial is

aligned so that its MSB is adjacent to the leftmost Logic 1 of the

data. An exclusive OR (XOR) function is applied to the data to

produce a new, shorter number. The polynomial is again aligned so

that its MSB is adjacent to the leftmost Logic 1 of the new result,

and the procedure is repeated. This process is repeated until the

original data is reduced to a value less than the polynomial.

This value is the 8-bit checksum.

Example of a Polynomial CRC Calculation—24-Bit Word:

0x654321 (Eight Command Bits and 16-Bit Data)

An example of generating the 8-bit checksum using the

polynomial based checksum is as follows.

Initial value

011001010100001100100001

01100101010000110010000100000000

left shifted eight bits

x8 + x2 + x + 1 =

100000111

polynomial

100100100000110010000100000000

XOR result

100000111

polynomial

100011000110010000100000000

XOR result

100000111

polynomial

11111110010000100000000

XOR result

100000111

polynomial value

1111101110000100000000

XOR result

100000111

polynomial value

111100000000100000000

XOR result

100000111

polynomial value

11100111000100000000

XOR result

100000111

polynomial value

1100100100100000000

XOR result

100000111

polynomial value

100101010100000000

XOR result

100000111

polynomial value

101101100000000

XOR result

100000111

polynomial value

1101011000000

XOR result

100000111

polynomial value

101010110000

XOR result

100000111

polynomial value

1010001000

XOR result

100000111

polynomial value

10000110

checksum = 0x86.

AD4112BCPZ Datasheet(PDF) 39 Page - Analog Devices

AD4112BCPZ Datasheet(HTML) 39 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58

Datasheet Download

Link URL