unsigned long long d_mask; // masks access_code bits (top N bits are set where
// N is the number of bits in the access code)
unsigned int d_threshold; // how many bits may be wrong in sync vector
unsigned long long d_mask; // masks access_code bits (top N bits are set where
// N is the number of bits in the access code)
unsigned int d_threshold; // how many bits may be wrong in sync vector