| 摘要 |
PROBLEM TO BE SOLVED: To prevent flag emulation in the data communication device, where a frame border is represented by a flag pattern. SOLUTION: When a flag correlation detection circuit 12 detects a flag pattern similar to a flag pattern from transmission data, the circuit 12 outputs an emulation detection pulse. An OR circuit 13 ORs a frame synchronizing signal and emulation detection pulse of the flag correlation detection circuit 12 and provides an output. A flag insertion circuit 15 inserts the flag pattern based on an output pulse from the OR circuit 13. Thus, when there is a similar flag pattern in the transmission data, the flag pattern is inserted immediately after the similar flag pattern. |
