| 摘要 |
PURPOSE:To prevent generation of a data omission and a double transfer of data, and to execute an exact retry, in case of a retry of a processing device, by providing a one shot FF circuit and a delaying circuit, etc. CONSTITUTION:When an XSTROBE signal is outputted from a processing device, an XDEMAND signal outputted from an FF8 through one shot FFs 6 and 7, etc. falls. As a result, when the XSTROBE signal from the processing device stops, an off-line signal outputted from an FF14 through gate 5, the FF8, etc. is inverted, and delayed for a constant interval of time by a delaying circuit 16. During this delay time, an I/O receives the XSTROBE signal from the processing device and executes a data input processing. Subsequently, after this processing is completed, the I/O becomes to be an on-line through an FF15, by which generation of a data omission and a double transfer are prevented at the time of a retry of the processing device, and an exact retry can be executed. |
