| 摘要 |
PURPOSE:To perform securely data transmission even when mirocomputers are coupled directly with each other through a data bus, by starting and ending the data transmission after interchanging conformation signals mutually. CONSTITUTION:A micrcomputer 1 sets 0 to an output port P10 firstly to generate an interruption control signal. Then, the micrcomputer 1 supplies a data transmission enquiry signal from an output port P11 to a microcomputer 2. The computer 2, on the other hand, sends a data transmission acceptance signal from an output port P21 when an input port P22 changes to 0. On confirming this signal, the computer 1 transmits data from input/output ports P13-P1n to the computer 2. The computer 2, on the other hand, fetches the data supplied to input/output ports P23-P2n once detecting the inversion of the input port P22 from 0 to 1. After this fetching operation is completed, 1 is set to the port P21. Consequently, the computer 1 releases a bus line 7. |
