| 摘要 |
PURPOSE:To obtain a pattern detecting circuit independently of the number of patterns by converting N-bit parallel data to a prescribed pattern and obtaining the number of bits coinciding with corresponding bits of a detection pattern by an adding part and detecting the pattern with a comparator having a (N-M)-bit threshold level. CONSTITUTION:16-bit components of N-bit (for example, 16-bit) serial data 1 are stored in a register 50 synchronously with a clock 2 and is sent to a decoder 60 as parallel data. If inputted data 1 is equal to detection pattern '1001001100110110', 16 '1's are sent to a counter 70 from the decoder 60 by NOT circuits in parts corresponding to bits of detection pattern '1001001100110110'. The counter 70 counts the number of '1's, and the counter 7 outputs '10000' when a counted value 16 is obtained as coincidence of all bits but outputs '01111' when a counted value 15, namely, one bit error is obtained. A comparator 80 sends signal '1' from an AND 81 as a pattern detection signal 3 through an OR 83 if the output of the counter 70 is '10000', but the comparator 80 sends signal '1' from an AND 82 as the pattern detection signal 3 through the OR 83 if the output of the counter is '01111'. |
