| 摘要 |
PURPOSE:To simply and swiftly write in a data input circuit the data of which data length is longer than that of a microprocessor by connecting the address data bus of the microprocessor with the data input bus of the data input circuit. CONSTITUTION:Among the address data buses from the microprocessor 1, a bus 12, in case herein taken, functions as a circuit selecting line to select either of a program memory 2 and the data input circuit 3, and is connected directly with the circuit 3, but is connected with the memory 2 through an inverter 4. A bus 13 constitutes an address signal line leading to the memory 2 and the circuit 3, and is connected directly with the memory 2 and the circuit 3. To write data from the microprocessor 1 to the circuit 3, several bits of the address string of the write instruction are used as a part of the write data, and are transmitted to the circuit 3 by the bus 11. The selecting of the circuit 3 is performed using the remaining data 12 and 13. Therefore, a data longer than the data length of the processor 1 is able to be written by using one instruction. |
