RECORDER FOR HISTORY OF COMMON BUS INFORMATION

PURPOSE:To record the information of a bus cycle as a history by recording the number of repetitions of the information of the continuous bus cycle when the bus cycle of the same bus information is continued. CONSTITUTION:One cycle is performed by the common bus 11, and the information A is set to the first register 2. In a comparison circuit 5, the contents of the first register 2 are compared with the contents of the second register 3, when both coincide, a coincidence pulse is outputted and a counted value is recorded in a counter 6. In the next bus cycle, the bus cycle information A of the preceding time stored in the first register 2 is set to the second register 3. The contents of the register 2 is recorded in the first memory 8, and the counted value of the counter 6 is recorded in the second memory 9. An information history recording means is constituted of the first memory 8 and the second memory 9.