The TNETE211 interfaces the ThunderLAN TNETE100's IEEE 802.3u media independent interface to an IEEE 802.12 physical media-dependent device for 100VG-AnyLAN operation. The TNETE211 is responsible for quartet channeling, scrambling the transmission data into five-bit data quintets, and encoding the resulting quintets into six-bit (5B6B) symbols. The TNETE211 also adds the preamble, start-frame delimiter, and end-frame delimiter to each channel. Quartet channeling refers to the process of dividing the MAC frame data octets into five-bit data quintets and alloting them sequentially among the four transmission pair channels. The data scrambler alters the five-bit quintet into a randomized bit pattern which is helpful in reducing radio-frequency interference and signal cross talk between channels. The 5B6B symbol encoding transforms the five-bit randomized pattern into predetermined six-bit symbols. This provides a balanced data pattern with an equal number of zeroes and ones for clock transition synchronization for receive circuitry. This symbol encoding also has the added benefit of being an error-checking mechanism. Compliant with IEEE Standard 1149.1-1990 (JTAG), the TNETE211 provides a five-pin test-access port that is used for boundary-scan testing. The TNETE211 is available in an 80-pin plastic quad flat package.