| 摘要 |
PURPOSE:To carry out a high speed data transfer between host device and a data buffer certainly by monitoring the difference of the number between a data transfer demand signal and a data transmission signal and controlling the transmission of a data transfer demand signal. CONSTITUTION:A data transfer controller transmits a data demand signal 1 to a host device from a data demand signal preparation circuit 5. After the transmission of the data demand signal 1, the host device transmits a response signal 1, transfers a data 3 to a buffer 4 after a constant time, and a pointer circuit 6 stocks it in the specified place. The transission number of the data demand signal 1 is calculated by an up/down coumnter 8. When the counted number is the same as that of the buffer 4 capacity, a transmission stop signal 5 of the data demand signal 1 is outputted from the up/down counter 8 to a data demand signal preparation circuit 5 to terminate the transmission of the data demand signal 1. |
