Microprocessor having built-in DRAM and internal data transfer paths wider and faster than independent external transfer paths

摘要

A microprocessor having a built-in DRAM performs following processes: data stored in the buffer 14a is transferred to the DRAM 16 through the internal bus 15 whose data transfer speed is higher than that of the system bus 13a, the transferring occurring when the number of data input operations by the bus interface unit 14 reaches a predetermined number "p", and an operation result obtained by execution of the CPU 17 and then stored in the DRAM 16 is read through the internal bus 15 and then output to the system bus 13b.