| 摘要 |
PURPOSE:To heighten a processing efficiency a compact and simple construction by providing an adjusting portions for controlling an access to a data memory from an external interface portion and a transmission part or a transmission receiving part in a transmission part and a receiving portion respectively. CONSTITUTION:In a transmission part 6, a transmission division 8 carries out a transmission in a fixed period, and reads a transmission data from a data memory 9. In an external interface part 7, when a reload request of a transmission data is issued from CPU outside the device, the data is written in a memory. At this time, a data reading request of the transmission division 8 is registered with the data reload request from the interface part 7 in time, a time adjustment is done in an adjusting part 10. Therefore, the memory 9 is constructed in a double buffer construction for transmission and an interface. At a time when the writing of the data by the interface part 7 is finished, the adjusting portion 10 outputs a switching signal 14 and changes over a switch 13 to the transmission division 8. In a receiving section 15, similarly the memory 9 is controlled by the adjusting part 10. |
