Error detection and correction: cyclic redundancy check
consider the cyclic redundancy check (crc) algorithm discussed in section 5.2.3 of the text. suppose that the 4-bit generator (g) is 1001, that the data payload (d) is 1000 and that r=3.
 what are the crc bits (r) associated with the data payload of d = 1000, given that r=3?

[hint: recall from the text that in calculating the crc bits, all crc calculations are done in modulo-2 arithmetic without carries in addition or borrows in subtraction. this means that addition and subtraction are identical and both equal to the bitwise exclusive-or (xor) of the operands. if you'd like to review modulo-2 binary arithmetic, here is a nice site that provides a modulo-2 binary arithmetic calculator, and provides explanations of the calculations.]