| 摘要 |
PURPOSE:To form an in-circuit emulator which is free from the using limit of internal interruptions by switching the bus of a microprocessor to the emulator side after detecting that an interruption of high priority is executed and holding the contents of a stack. CONSTITUTION:An interruption execution detecting means 1 detects the occurrence of a non-maskable interruption NMI by the output of a flip-flop 16 and monitors the address of an address data bus 13. When a specific interruption vector address showing the execution of the NMI is outputted, the means 14 sets the output PA at a low level to clear the flip-flop 16 and simultaneously controls a bus switching means 11 to separate a target system 1. A memory part control means 20 controls a memory part 21 by the output STACK of the means 14 and stores the contents stacked with the occurrence of an interruption into the part 21. In such a way, the interruption of high priority such as the NMI is always produced after the interruption produced at a break point. |
