On a 17 inch monitor, you can see the two slides side by side
-
If the number of 1 bits in a column is 0, 2, 4, 6, 8, etc. then you
set the mod 2 sum equal to 0. It is just like even parity in that
respect.
-
If the number of 1 bits is odd, i.e. is 1, 3, 5, 7, 9, etc. then
you set the mod sum for that column to 1.
Hamming
codeword practice questions (see #4, #5, #6 and #7).
Animation of hamming codewords concept.
What if the Hamming codeword for the letter k
was received with ONE of the bits being an error and the opposite of what
it should be?
- Suppose that the receiving computer takes the 8 data bits
as the
ASCII code for a left brace "{" instead of the
ASCII code for "k".
Can you tell me what bit was wrong when the Hamming codeword was
received?
- Suppose the receiving computer 8 data bits indicate "j" instead of
"k". What happened during the data transmission if only one bit
was in error?
- Suppose the receiving computer 8 data bits indicate "i" instead of
"k". What happened during the data transmission if only one bit
was in error?
- Suppose the receiving computer 8 data bits indicate "c" instead of
"k". What happened during the data transmission if only one bit
was in error?
- Suppose the receiving computer 8 data bits indicate "o" instead of
"k". What happened during the data transmission if only one bit
was in error? What bit was in error for lower-case o ASCII
pattern to be stored in the data bits locations of the ASCII
code word? Lower-case O, i.e. little "oh" character "o".
- Suppose the receiving computer 8 data bits indicate "K" instead of
"k". What happened during the data transmission if only one bit
was in error and the data bits at locations 12, 11, 10, 9, 7,
6, 5, and 3 indicate an UPPER-CASE "K" instead of a lower-case "k"?
- CRC example 1 and
CRC example 2 and
Quiz questions to try
out.