Patent ID: 7313751

Claim:
A micro stage comprising: an MB810 decoder; an 8B/10B decoder; a mode detection unit which detects a decoder to be used as an operation decoder between the MB810 decoder and the 8B/10B decoder; a first low pass filter which when the MB810 decoder is determined as the operation decoder, removes a predetermined frequency bandwidth from a 10-bit code input from the outside; a second low pass filter which when the 8B/10B decoder is determined as the operation decoder, removes a predetermined frequency bandwidth from a 10-bit code input from the outside; an IDLE code detection unit which detects IDLE code from the 10-bit code and transfers to the mode detection unit; a first switch unit which according to the decoder determined as the operation decoder, selectively outputs the 10-bit code input from the first low pass filter and the second low pass filter; a parallel conversion unit which converts the 10-bit code input from the first switch into a parallel code and outputs a 10-bit parallel code; a first selection unit which provides the 10-bit parallel code to the decoder determined as the operation decoder between the MB810 decoder and the 8B/10B decoder; and a second selection unit which selectively outputs an 8-bit code corresponding to the 10-bit parallel code input from the decoder determined as the operation decoder, wherein by performing a mode detection process based on IDLE codes detected from the 10-bit code input by the IDLE code detection unit, the mode detection unit detects a decoder to be used as an operation decoder between the MB810 decoder and the 8B/10B decoder, and the mode detection process comprises: initializing a counter counting the number of IDLE codes; receiving a first code from the IDLE code detection unit and increasing the counter by a predetermined increasing amount; checking whether the first code is +K28.7 code or −K28.7 code; if the first code is +K28.7 code or −K28.7 code, increasing the counter by a predetermined increasing amount and receiving a second code following the first code from the IDLE code detection unit; checking whether the second code is +K28.7 code or −K28.7 code; if the second code is +K28.7 code or −K28.7 code, checking the number of K28.7 codes continuously input from the IDLE code detection unit, and if the number of K28.7 codes continuously input from the IDLE code detection unit is less than a predetermined first reference number, performing the receiving a third code from the IDLE code detection unit, and if the number of K28.7 codes continuously input from the IDLE code detection unit is equal to or greater than the predetermined first reference number, determining the MB810 decoder as the operation decoder; if the first code is +28.7 code and the second code is not −K28.7 code or if the first code is −28.7 code and the second code is not +K28.7 code, determining that there is an error in transmission lines and performing the initializing a counter counting the number of IDLE codes, or transmitting a test code.