摘要 |
The invention relates to a circuit arrangement and to a method for creating and retrieving replacement data. The circuit arrangement has a programmed ROM, which is coupled to a patch-memory module through an address and data bus. The patch-memory module has a plurality of patch-data registers and patch-address registers, in which the addresses and replacement data are stored. The invention makes it possible that a hard-wired and thus irreversibly programmed ROM can be modified and corrected by an external circuit arrangement. For example, erroneous instructions of program sequences and data can be replaced by error correction instructions during a ROM access of the program-controlled unit. By using dedicated registers, the RAM essentially can be dispensed with for error correction, while retaining the retrieval speed.
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