| 摘要 |
PURPOSE:To relieve the load on a microprocessor by providing a message extract circuit comprising a hardware and giving its command only by the microprocessor. CONSTITUTION:An input signal is inputted to a data word extract section 1-4-2 and a shift register 1-4-5. On the other hand, a microprocessor 1-6 designates a DSAT color code by a signal DM and a DSAT pattern generator 1-4-3 outputs a corresponding DSAT pattern. Moreover, the processor 1-6 sets a permissible error bit number to signals PM1, PM2 at scan search and shift search. A DSAT part of the data inputted to a shift register is compared with a DSAT pattern from a generating section 1-4-3 to check whether or not a range of an allowable error exceeds the value set in the signal PM1. A synchronization word is detected by a synchronization word detection section 1-4-4 and it is used to trigger for data word extraction. The extract section 1-4-2 regards a predetermined bit after synchronization word detection as a data bit and samples only an even numbered bit. |
