| 摘要 |
PURPOSE:To attain easily the execution at rising, by providing a memory bus RAM/ROM switching control line and executing a prescribed specific program with an ROM and a usual changing program with an RAM. CONSTITUTION:The RAM2 and the ROM3 are connected to a CPU1 via a memory bus 10. The bus 10 consists of a data line 11, a memory address line 12 and a control line 13. The line 13 includes an RAM/ROM switching control line 14 to give an RAM/ROM switching control signal to the RAM2 and the ROM3. Thus, the RAM2 and the ROM3 are used distinctively with the RAM/ROM switching control signal when the RAM2 and the ROM3 are set for memory addresse 0-4k addresses, in taking the memory capacity of the RAM2 and the ROM3 as 4k-word. |
