Assignment:

A - ISBN Checksum Generator

Use Keil uvision software to write and simulate an ARM assembly program that generates a valid ISBN checksum for a given ISBN.

B - ISBN Checksum Validator Use Keil uvision software to write and simulate an ARM assembly program that checks the validity of a given ISBN by verifying the checksum

Helping Information

An ISBN consists of nine digits plus a validation digit.

The digits are numbered from right to left as d1, d2 ... d10, with d1 being the validation digit.

You can define the ISBN number in a 10-byte array in the memory. Each digit is stored in a byte.

To check whether the ISBN is valid or not, the following calculations are performed:

Result = (10 x d10 + 9 x d9 + + i x di + + 2 x d2) % 11

Calculate d1 = 11 Result 2

If the calculated d1 equal to the d1 in the input ISBN then it is valid

If d1 = 10, it is written 'X'

For example, given the following ISBN:

ISBN = 5123487654

ISBN = 5 1 2 3 4 8 7 6 5 4

d10 d9 d8 d7 d6 d5 d4 d3 d2 d1

Result = x 10 + x 9 + x 8 + x 7 + x 6 + x 5 + x 4 + x 3 + x 2 mod 11

= 216 mod 11 = 7

d1 = 11 Result

= 11 7 = 4 ,

then the input ISBN is valid, since the calculated d1 is equal to the d1 in the input ISBN.

Some ISBN examples:

The ISBN 5123487654 is valid

The ISBN 5123487658 is not valid

The ISBN 7465159237 is valid

The ISBN 7465159232 is not valid

The ISBN 123456789X is valid

The ISBN 1234567891 is not valid