| 摘要 |
PURPOSE:To perform data conversion at high speed by providing a decoder which inputs an address signal for input device selection from a microprocessor MP and a read-only memory which reads the contents of an input device and outputs them to the data bus of the MP. CONSTITUTION:An output enable terminal OE is signified with an input device read signal IR from the MP 1. The contents of the read-only memory 3 in an address indicated by an address bus AH currently, i.e., address indicated by the contents of the accumulator in the MP 1, and the output DO is sent to a data bus DB. The MP 1 inputs the data on the bus DB to the accumulator. Data before conversion is used as an address input AI to write contents which become data after conversion in the memory 3 in the address corresponding to the data. For the purpose, the data before conversion is put in the accumulator for the conversion processing of the MP 1 and an input instruction is executed by a data converter to obtain the data after the conversion in the accumulator. |
