Patent ID: 7012936

Claim:
An initialization method for use in a ring-shaped network comprising a plurality of stages of data transmission apparatuses, each performing data transmission while assigning one or more bits of data as one data symbol to a signal level, one data transmission apparatus being a master data transmission apparatus, any remaining data transmission apparatuses being slave data transmission apparatuses, said initialization method comprising: outputting a first initialization pattern signal from the master data transmission apparatus to a slave data transmission apparatus in a next stage upon turn-on of power or immediately after reset; establishing clock synchronization via the next-stage slave data transmission apparatus upon receipt of the first initialization pattern signal; outputting the first initialization pattern signal from the next-state slave data transmission to a slave data transmission apparatus in the following stage when clock synchronization is established; outputting a second initialization pattern signal from the master data transmission apparatus to the next-stage slave data transmission apparatus after outputting the first initialization pattern signal; setting an evaluation level for each signal level via the next-stage slave data transmission apparatus when the next-stage slave data transmission apparatus receives the second initialization pattern signal; outputting the second initialization pattern signal from the next-stage slave data transmission apparatus to the slave data transmission apparatus in the following stage; and starting transmission/reception of data in the data transmission apparatuses connected in the ring-shaped network after establishing the evaluation levels.