Mitsubishi Denki Kabushiki Kaisha

Nec Corporation

Mitsubishi Denki Kabushiki Kiasha

Naohiro Kobayashi

Masayuki Koyama

For each of a plurality of basic circuit regions arranged in an array, a holding circuit for holding write inhibit information is provided. A region to be used for the IP can arbitrarily be selected from the plurality of basic circuit regions for writing first circuit information. Therefore, after various IPs are written by the first writer, efficient use of the remaining basic circuit region by the user and writing of second circuit information are enabled while preventing access to the circuit information for the IP by the user.

Programmable semiconductor device providing security of circuit information

Information for defining a structure of an address bit arrangement of a ROM portion of layout data is affixed, by means of text data as a discriminator, to a typical ROM cell portion indicating a characteristic of the address bit arrangement. Layout data including the affixed information is read in. ROM coordinate information and the text data are extracted. A ROM definition for generating a mask pattern is generated from the extracted ROM coordinate information based on ROM data. Thus, the layout information generating apparatus extracts the arrangement information and coordinate information of a ROM portion automatically, not manually, to generate a ROM definition, thereby considerably decreasing the number of steps to improve productivity.

Layout information generating apparatus and method thereof

It is possible to continuously obtain the function of FILO for plural sets of data while reducing regions for storing the data. A string of data input from a memory M0 is shifted to a memory M3, and is switched back and read from the memory M0. Consequently, the function of FILO can be obtained for the same string. On the other hand, a string of data input from the memory M3 is shifted to the memory M0, and is switched back and read from the memory M3. Consequently, the function of FILO can also be obtained for the same string. With these two data strings keeping a push-pull relationship each other, the data are shifted among the memories M0 to M3. Therefore, the number of elements of each data string is enough for that of required memories.

Bidirectional transfer type storage and method for controlling input and

A bidirectional FILO capable of continuously performing the function of the FILO for different groups of codes is used to reduce a circuit scale of a Reed-Solomon error correcting device. Coefficients of an error-locator polynomial .delta.(x) and an error-evaluator polynomial .omega.(x) obtained by using a Euclid method are obtained in order from a final digit of a code to a first digit thereof. Correspondingly, a corrector starts a Chien search in order from a final byte of the code to a first byte thereof. In response to the order of the search, each group of data RSIN (Reed-Solomon Input) having digit order reversed in a bidirectional FILO are given to the corrector. The code corrected by the corrector also has digit order reversed. Therefore, the digit order is returned to original order in the bidirectional FILO for returning digit order to original order, so that a code RSOUT (Reed-Solomon Input) is output. The bidirectional FILOs can be implemented by operation of a shift register type, for example.

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Tokyo, Japan

Naohiro Kobayashi