US Patent 7734992 Path memory circuit

A path memory circuit for use in a Viterbi decoding process performed based on state transitions through a number n (n is a positive integer) of states. The path memory circuit includes a memory area A formed by the storage circuits of the first to ith (i is an integer from 0 to M) stages; a memory area B formed by the selective storage circuits that select and hold a decoding result for any state k (k is integer from 1 to n) of the storage circuits from the i+1th stage to the Mth stage; and a memory area C formed by the selective storage circuits other than the memory area A and the memory area B.