US Patent 7479906 Multispeed communications device

A physical layer device comprises a mode selector that selects a mode. A clock selects a clock frequency from T clock frequencies based on the mode. A converter module selects one of N mapping functions based on the mode and converts an n-bit input to an m-bit output based on the selected one of the N mapping functions. A scrambler module scrambles the m-bit output or passes the m-bit output unchanged based on the mode. An encoding module modulates the m-bit output based on the selected clock frequency and one of M modulation modes selected based on the mode, where T, n, m, N and M are integers greater than one and n is not equal to m.