| 主权项 |
1. An error detection method comprising the steps of:
providing a finite state machine having t registers coupled together in series and operative to generate a periodic sequence of states (s1, s2, . . . , sr), (s1, s2, . . . , sr), (s1, s2, . . . , sr), . . . ; representing the nth state in the sequence with a set oft state variables sn=an1, an2, . . . , ant; at an initial state i,
providing starting values for the t state variables ai1, ai2, . . . ait and for a check parity Zi;computing a delta parity dZi as a function of a first set of zero or more of the state variables, andcomputing a predicted parity NZi as (Zi XOR dZi); for states in the sequence following the initial state,
setting the check parity Zn+1 equal to the predicted parity NZn,computing a state machine parity Pn+1 as sequentially XORed values of the state variables such that Pn+1=(a(n+1)1 XOR (a(n+1)2 XOR ( . . . XOR a(n+1)t))), andcomputing a total parity Tn+1 as (Pn+1 XOR Zn+1); and, selecting feedback to the first register, the function dZi, and the first set of state variables such that single point errors in the state of the machine are detected by total parity Tn+1. |
