| 摘要 |
PURPOSE: A device for detecting a specific data pattern is provided to correctly detect a specific data pattern by using a clock performing M frequency-multiplying of a clock for data synchronization, in a digital communication system. CONSTITUTION: A digital communication system has a function detecting a specific data pattern composed of N-bit in data transmitted after synchronized to a clock for data synchronization having a predetermined period. A device for detecting a specific data pattern comprises a frequency multiplier(302), a shift register(304), an exclusive NOR processor(308), a storage(310), an adder(312) and a comparator(314). The frequency multiplier(302) multiplies a frequency of the clock for data synchronization having a predetermined period. The shift register(304) stores input data with a N-by-M structure multiplying the N-bit and a M-bit, with shifting by one bit, by being synchronized to a clock signal output from the frequency multiplier. The exclusive NOR processor(308) performs an exclusive NOR processing, by being synchronized to a clock signal output from the frequency multiplier, and allocating data of the M-bit stored in the shift register to every one bit of the specific data pattern. The storage(310) stores a result of the exclusive NOR processing by the N-by-M bit. The adder(312) adds a value stored in the storage by the bit. And the comparator(314) outputs a detection signal with an active state, when a result added in the adder arrived to a predetermined threshold value.
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