ECE-C690: Dependable Computing
Homework 3
February 25, 2009
The homework is due in class Monday, March 9, 2009.
Each problem is worth 10 points.
1. Textbook problem 3.6.2
2. Textbook problem 3.6.3
3. Textbook problem 3.6.21
4. Show the organization of a 8-bit memory with Hamming single-error correction. Describe the organization
clearly and show the parity groups that result. Associate the syndromes with the particular bit that they
identify as erroneous.
5. A Hamming single-error-correcting code has the following parity check matrix.
H=
d1d2d3d4c1c2c3
0 0 1 1 1 0 1
0 1 0 0 1 1 1
1 0 0 1 1 1 0
where (d1, d2, d3, d4) are the data bits and (c1, c2, c3) are the corresponding parity-check bits, respectively.
Suppose, we retrieve the word (d1d2d3d4c1c2c3) = (0111011) from memory. What was the data word that
was stored originally in memory.
1
