| 摘要 |
PURPOSE:To perform time synchronization with high accuracy by measuring transmission delay time, and correcting a time synchronizing frame by a time correction frame using a measured value. CONSTITUTION:An SD detection circuit 3 detects an SD(start delimiter) representing the leading position of the time synchronizing frame inputted from a LAN controller 1 as a transmission data signal S1. A counter control circuit 4 measures a time until the SD is detected after the transmission request of the time synchronizing frame is issued from a count number, and measures the transmission delay time. A CPU supplies transmission delay time information to the controller 1, and the controller 1 sets the delay time information on the time correction frame, and transmits it to a reception side. The reception side, when receiving the time correction frame, corrects a time based on the content of the frame, and completes a synchronizing operation after transmitting a reception response signal. |
