| 摘要 |
<p>PURPOSE:To omit an I/O port, a counter, etc., by providing a circuit which produces a single-step interruption by an internal timing signal and a selector which selects a normal action or an internal single-step action. CONSTITUTION:A single-step control circuit consists of a delay circuit 4, a flip-flop 5, and a selector 6 which performs switch between an external supervisor interruption 11 and a single-step interruption 10. A single-step interruption is produced within a processor by the existing timing and therefore a single-step action is possible with a small number of additional circuits. At the same time, an external supervisor interruption answer signal is outputted like an external supervisor interruption even in an internal single-step interruption mode owing to use of a selector that can select a normal action or a single-step action. As a result, the internal single-step interruption can be processed like the external supervisor interruption.</p> |
