| 摘要 |
PURPOSE:To transfer data surely by sending a start signal from the first microcomputer to the second microcomputer and sending back clocks from the second microcomputer to the first microcomputer and transferring data from the first microcomputer to the second microcomputer. CONSTITUTION:In case of data transfer from the first microcomputer A to the second microcomputer B, a start bit which falls from the high level to the low level at a timing t1 is sent from the microcomputer A to the microcom puter B to report the start of data transfer. Then, the microcomputer B detects the start of transfer and sends a clock to the microcomputer A at a timing t2. When receiving the clock after sending the start bit, the microcomputer A judges that the microcomputer B detects the start of transfer, and the micro computer A sends the first data, for example, the high level immediately. After reading this data H at a timing t3, the microcomputer sends the next clock to the microcomputer A at a timing t4. hereafter, data are sent and read and clocks are sent repeatedly at timings t5, t6- similarly. |
