SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To efficiently transfer data between a memory and an I/O device with respect to a semiconductor device arranged among a CPU, the memory and the I/O device so as to act as a data transfer bridge. SOLUTION: A CPU interface 11 and I/O interfaces 13 to 15 in a bridge chip 1 are connected to a DRAM interface 12 through an internal bus 10. These I/O interfaces 13 to 15 are respectively provided with read/write buffers 21 to 23 and DMACs 26 to 28. An arbiter 17 determines a bus master to be permitted in accordance with requests of data transfer with a DRAM 3 which are outputted from the CPU interface 11 and respective DMACs 26 to 28. Each of the I/O interfaces 13 to 15 has a function for controlling data transfer with the DRAM 3 so as to transfer data by skipping a part of areas in the DRAM 3.