A New Methodology for Reducing Switching Activity in Serial Links of SoC

As technology advances, the number of on-chip module will increase. Long and multi-bit parallel buses between these modules may cause several problems such as skew, cross-talk, wiring difficulty, and large area. Serial communication has many advantages over multi-bit parallel communication. Multiplexing parallel buses into a serial link enables an improvement in terms of reducing interconnect area and cross-talk, but it may increase the overall switching activity factor. Therefore, an efficient coding method that reduces the switching activity is an important issue in serial interconnects design. Most existing coding techniques in serial links like Bus-Invert coding and Transition Inversion Coding (TIC) need an additional bit for indicating the encoded data. This extra bit not only increases the number of transmitted bits, but also increases the transitions and switching activity. The new coding technique called Embedded Transition Inversion (ETI) coding is used for low switching activity in serial links. It uses the phase difference between the clock and the encoded data to avoid the problem of an extra indication bit.