A METHOD FOR ARRANGING A READ - ONLY MEMORY FOR READING OUT UPDATING STATUS INFORMATION IN AN INTEGRATED CIRCUIT

The present invention relates to a method for arranging a read memory for reading electrically updating status information from an integrated circuit (3) which comprises various circuit layers. Patterned circuit layers, so-called pattern layers, are produced, for instance, from a respective mask which has been made particularly for each of the pattern layers. According to the invention, each pattern layer in which reconstruction can be made has provided therein a separate memory device, such that when changes are made in one such pattern, the updating status of the pattern layer can be written into the memory device in code form. The memory devices included in an integrated circuit form a read-only-memory which is programmed so that the pattern layers in which a memory device is provided contain a code which is individual to its own updating status. At the same time as the updating status code is written into the memory device, the code is also written into a test device (2) as reference information. When checking the circuit, a test program (5) in the test device (2) reads the updating statuses of the pattern layers and compares them with the reference information, the result of this comparison indicating the updating status of the integrated circuit.