Th is Exercise examines the single error correcting, double error detecting (SEC/DED) Hamming code.

1. What is the minimum number of parity bits required to protect a 128-bit word using the SEC/DED code?

2. Section 5.5 states that modern server memory modules (DIMMs) employ SEC/DED ECC to protect each 64 bits with 8 parity bits. Compute the cost/performance ratio of this code to the code from 5.9.1. In this case, cost is the relative number of parity bits needed while performance is the relative number of errors that can be corrected. Which is better?

3. Consider a SEC code that protects 8 bit words with 4 parity bits. If we read the value 0x375, is there an error? If so, correct the error.