| 摘要 |
PURPOSE:To easily detect an abnormal position and to shorten time required for error repairment by allowing a control part to judge whether data transfer is being executed or not by an identifier(ID) stored in a control register, and when data transfer is not executed, execute self-diagnosis. CONSTITUTION:A control register 15 is divided into register areas 15a to 15c corresponding to plural data transfer circuits 13a to 13c, and for instance the VOL code of a data group converted by the circuit 13a is set up in the area 15a. When the final EOV code is sent after completing data transfer from the circuit 13a to a memory area 14a, the VOL code in the area 15a is set up. Similar operation is applied also to the circuits 13b, 13c. The control part 11 monitors whether the VOL code is set up in the register 15 or not, and if the VOL code is reset, judges that any data transfer circuit is stopping data transmission/reception to/from the CPU and executes self-diagnosis. |
