摘要 |
Improvement in a numerical control unit which executes a data processing using the computing function of a processor. The numerical control unit by itself has an address-stop function suitable for discovering a software error, that makes it possible to discover a problem early without using a special unit for developing software. For discovering the cause of a problem in some circuit, first the address of the circuit is set into a higher register (10) and then a program is executed. If the circuit is given normal access, and address-coincidence detecting circuit (20) interrupts the processor, so that the display of the register contents is accurate and suited for the actual processing. Unless given normal access, no interruption is caused, or an uncorrect register contents are displayed even if the interruption is caused. Thus, it makes it possible to discover a problem in software. |