Synchronization methods, apparatus and systems are disclosed. The bus further enables the wireless connection of peripheral components to a computing device, thereby providing a distributed computing device. Then, from among a plurality of divided sub-frames, data read in during the first divided sub-frame period is stored in memory of each pixel, and the stored data is read out during other divided sub-frame display periods and display is performed. A preceding coded signal is used as a feedback signal and a feedforward signal for enabling natural numbers to be used as the result of coding, thereby markedly improving the secrecy security of coded signal. The auxiliary recording layer is exchange-coupled with the adjoining first recording layer and second recording layer.