| 摘要 |
PURPOSE:To prevent a debugging microprocessor from being stopped by the re-occurrence of bus error during interrupt handling by saving the bus error state, which indicates whether the exception handling due to bus error is executed or not, at the time of the occurrence of interrupt and restoring the save bus error state to a bus error detecting circuit at the time of return from the interrupt. CONSTITUTION:A bus error state storage circuit 4 is provided, and the bus error state indicating whether the interrupt occurs during the exception handling due to bus error or not is saved in the bus error state storage circuit 4 to set a bus error detecting circuit 1 to the bus error absence state before bus error detection at the time of the occurrence of the interrupt from a debugging interrupt request terminal 12, and the saved bus error state is restored to the bus error state storage circuit 4 to the bus error detecting circuit 1 at the time of return from the interrupt. Consequently, the interrupt handling is started in the bus error absence state whether the bus error processing is executed before the start of the interrupt handling. Thus, the debugging microprocessor is not stopped by the re-occurrence of bus error during the interrupt handling. |
