| 摘要 |
<p>PURPOSE:To make an accumulation time constant and to improve transmission effi ciency even at the time of the lowest communication speed by detecting a change point and setting automatically the most suitable accumulation quantity of a buffer memory even when the communication speed or input data changes to various speeds. CONSTITUTION:A holding part 3 holds a measured value Ro of a communication speed measuring part 2 when used for accumulation quantity control at the last time. a comparing part 4 compares the measured value Ro at the last time held by the holding part 3 with a measured value R at this time and when their difference exceeds a fixed value set beforehand, it is recognized that the communication speed changes and an updatimg control signal C is outputted. An accumulation quantity control part 5 generates a reset signal C1 and a clock control signal C2 by the updating control signal C of the output of the comparing part 4 and the reset signal C1 empties the storage data of a buffer memory 1. After that, the clock control signal C2 controls a clock controller 6 and stops the input of a reading clock CKr of the buffer memory 1. Thus, the data of a quantity corresponding to the measured value R of the newest communication speed are accumulated in the buffer memory 1 and the transmission efficiency can be improved.</p> |
