| 摘要 |
PURPOSE:To prevent data on a memory from being changed even when a fault is generated and to enable the fault to be analyzed, by reading out the data written on a RAM card when an abnormal operation is performed. CONSTITUTION:At a sample signal selection circuit 7, the sample signal SP of the data to be filed in the RAM card is set. A trigger condition to set a signal which interrupts trace when an abnormal state is detected is set, and it is written on an address up comparison circuit 13, an address lower circuit 14, and a data comparator 15 from a CPU. Next, the data is set at a RAM card write stoppage trigger selection circuit 12 which validates the signal from the circuits 13-15. When the RAM card 1 is set, a reset momentary switch 16 is operated, and an address from a RAM card address counter 11 is sent as the address of the card 1. By performing initialization and setting the card 1 as stated above, an MPU operation can be traced. Then, the readout of the data on the card 1 when the abnormal operation is generated can be realized.
|
