| 摘要 |
PURPOSE:To reduce the number of the steps and the processing speed of a program by using a microcode and selecting whether the address of data ROM is designated by a special address register or the address is designated by a general purpose register. CONSTITUTION:A microcode 19 has respective fields 20-23. The field 20 is a field to specify the contents of the operation to be processed, fields 21 and 22 specify the field operated by an operation and the field 23 is the one to operate a RAM pointer, a ROM pointer and a external memory pointer. By using a control field 23, the operation and designation of the general purpose address register are executed. For example, when the data at every 64 pieces are reading-processed, 3-step reduction can be reduced compared with a conventional processing and when the general purpose address register is used, the effect is every large. |
