Patent ID: 7986251

Claim:
An input/output (IO) interface comprising: a data encoder encoding each of a plurality of pieces of parallel data having different timings and generating a plurality of pieces of encoded data; and an alternating current (AC) coupling transmission unit transmitting the plurality of pieces of encoded data by performing an AC coupling method, wherein: the data encoder compares first parallel data with second parallel data from among the plurality of pieces of parallel data on a bit-by-bit basis and obtains a number of bits whose logic states have transited between the first parallel data and the second parallel data; when the number of bits whose logic states have transited is greater than or equal to a reference number of bits, the data encoder inverts bit values of the second parallel data to generate the encoded data, and when the number of bits whose logic states have transited is less than the reference number of bits, the data encoder maintains the bit values of the second parallel data to generate the encoded data; the data encoder generates encoding flags; when the encoded data is generated by maintaining the bit values of the second parallel data, the data encoder sets the encoding flags to have a first logic state; and when the encoded data is generated by inverting the bit values of the second parallel data, the data encoder sets the encoding flags to have a second logic state.