Being the device in order to generate interruption and the mannered null interruption mask impossible conversion

摘要

PURPOSE: To enable and disable interruption by a software by providing a structure for indicating software and hardware situations, and a structure for generating interruption when the assertion of an interruption request signal is generated. ;CONSTITUTION: When a processor is turned into an idle mode, an IDLE INDICA TOR CIRCUIT 22 asserts an IDLE signal on a line 24, the output of an OR gate 28 is turned to a high level, and as long as the level is held, a latch 10 is set by the assertion of an interruption request signal INTO on a line 4, and interruption is generated. Then, while the processor is in the IDLE mode, an interruption flag IEO is set by the assertion of the interruption request signal INTO, and even when the interruption is masked by software, it is recognized by the processor. Also, when the processor is not in the idle mode, the IDLE signal on the line 24 is remaining in a low level, and the possibility and impossibility of the interruption is decided by a SOFTWARE ENABLE signal on a line 26.;COPYRIGHT: (C)1994,JPO