| 摘要 |
<p>PURPOSE:To attain frame synchronization by an economical constitution without absence of data of one frame by making a decision that frames are out of synchronism when the detection of a flag word can not be continued more than fixed times and in synchronism when it can be done. CONSTITUTION:Frames are constituted with fixed word length and flag words indicating the boundary between frames are inserted so as to attain frame synchronization by detecting those flag words. By the interruption from transmission control part TC, processing part PS reads information on whether or not flag words are detected and when the detection of the flag word can not be done continuously more than fixed times, frames are considered to be out of synchronism. This decision causes flag search commond register REG to set so as to control counter CNT counting up bit clocks and when a flag word is detected, REG is reset. Further, when flag words are detected continuously more than fixed times, a decision that frames are in synchronism is made. The transmission errors of flag words can therefore be prevented unless the errors continue less than fixed times.</p> |
