METHOD AND EQUIPMENT FOR ENCODING AND DECODING LOGICAL SIGNAL

Japanese Patent JPH0738442

A

PURPOSE: To prevent a code error from occurring in transition coding. CONSTITUTION: In a transition coding system that encodes two transitions in each window, when a 3rd transition occurs in the same window, the 3rd transition is delayed to the next window. A transition detector 10 receives a signal Tx' corresponding to a signal Tx after processing is performed by a correction circuit 40. A comparator 42 receives the contents of a 4-bit counter 44 at an input A, and receives a binary-coded decimal value 11 at an input B. The counter 44 is clocked by a clock signal 16F, and is reset by a descending edge of a signal 1E. The comparator 42 is in its active state as long as the contents P2 of the counter 44 is smaller than eleven and supplies a signal P20K in its input A