| 摘要 |
PURPOSE:To obtain a microprocessor with a small mounting area suitable for load distribution processing by adhering two microprocessors formed in a face symmetry back to back. CONSTITUTION:Microprocessors 1, 2 formed in a face symmetry are adhered back to back. External memory access control circuits 12, 22 implement read control of a program conducted by CPUs 10, 20 from an external memory and write control to cache memories 11, 12. The contention produced by using one external bus 300 by two external memory access control circuits 12, 22 is avoided by providing priority to one as a master processor and giving a bus use right to an external memory access circuit belonging to the processor. Common sharing memories 16, 26 are accessed by both of the CPUs 12, 20 and the access contention produced by allowing both the CPUs 10, 20 to make simultaneous access is avoided by executing an access request from the master processor with priority. |
