| 摘要 |
PURPOSE:To inform assuredly overflow of a stack area to a CPU by writing data to a writing interruption area in case a read-out memory protection code is specified and at the same time an access code designates a writing action. CONSTITUTION:A specific memory protection code, e.g., '1011' is set in response to a writing interruption area 7. Then the memory protection code read out of an address conversion buffer 2 is equal to said code '1011'. Under such conditions, a check circuit 10 check whether an access code given from a CPU1 designates a writing action or not. In case the memory protection code is equal to '1011' and the access code given from the CPU1 designates a writing action, the circuit 10 sets an FF11 for interruption request. In such a case, an error detecting circuit 5 delivers no error signal and a memory access is carried out as it is. When this memory access is over, an interruption is information to the CPU1.
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