This paper presents an RTL-level model of an 8B/10B encoder/decoder block in SystemC. The use of 8B/10B coding is an important technique in the construction of high performance serial interfaces. These are particularly suitable for alleviating the I/O bottleneck of state of the art systems which are pinout, rather than bandwidth limited). SystemC has been chosen because it provides a homogeneous design flow for complex designs (i.e. SoC and IP based design), where system modeling at the early stages of the design becomes increasingly important.