| 摘要 |
PROBLEM TO BE SOLVED: To improve the throughput of an entire system by reading control information directly from a trailer buffer storing data in DMA transfer, when reception of frames is finished to eliminate the need for transferring the control information of the trailer section from a memory of a host layer. SOLUTION: A DMA controller 4 stores the contents of transfer to a trailer buffer 3 simultaneously, when DMA transfer of a received frame is conducted to a host layer RAM 8. When a reception control section 6 recognizes the start of reception, the control section 6 generates a reception start interrupt to a CPU 2. The CPU 2 sets a transfer destination address to the DMA controller 4, to start DMA transfer write to the host layer RAM 8. When the reception control section 6 recognizes the end of frame reception, the reception control section 6 completes DMA transfer and generates a reception end interrupt to the CPU 2. The CPU 2 reads the required byte number from the trailer buffer 3, and conducts protocol processings at the CPU 2. |
