| 摘要 |
<p>PURPOSE:To convert a virtual address into a real address by activating the access given to a memory cell array in response to a virtual address signal and a higher rank bit of the offset data and producing the real address signal in response to the virtual address signal and a lower rank bit of the offset data respectively. CONSTITUTION:A microcomputer 20 including a dual port random access memory DPRAM 5 is connected to a microcomputer 11 via an address bus AB1, a data bus DB1, and a control bus CB1 respectively. A detection circuit 27 produces an activating signal CE2 when an internal address signal set in a prescribed range is applied to an address bus AB2. The access given to the DPRAM 5 from a CPU 2 is activated in response to the signal CE2. Then the microcomputer 20 converts the virtual address signal produced from a microcomputer 11 into a real address signal used for the DPRAM 5. In such a way, a virtual address signal can be converted into a real address signal with no dependence needed on the arithmetic processing jobs of the CPU 2.</p> |
