| 摘要 |
PURPOSE:To accurately execute the data-reception monitoring by so forming the titled equipment that a memory access controller is directly activated by means of the reception of a flag, and monitoring, by sampling, the value of a byte-counting register of said controller in order to decide whether it is amid the receiving or already ended. CONSTITUTION:The receiving of data is performed by a direct-memory-access (DMA) transmission. The value of the byte-counting register 3a in the DMA controller 3 is at all time sampled since the data reception start state by a reception monitering equipment 5. The controller 3 steps as fetching the data other than the flag F ever since the start of the data-receiving, while the register 3a does as counting the data D. And, after the register 3a started the stepping, in case a variation of the counting value of the register 3a for a period of time that meets the transmission time of the data is not observed, the equipment 5 decides the reception as ended, and then proceeds to the next processing of the data analysis. In such a manner as described above, any data frame that has a flag pattern on both ends can be received and analized regardless of the difference of the format of transmission control procedure. |
