A method performed in a data communication interface, comprising: transmitting a first command to a plurality of devices coupled to a serial bus while the serial bus is operated in a first mode of operation, wherein the first command is transmitted in accordance with a first protocol to cause the serial bus to be operated in a second mode of operation; communicating with a first device of the plurality of devices in accordance with a second protocol while the serial bus is operated in the second mode of operation; and transmitting a second command to the plurality of devices in accordance with the first protocol to terminate the second mode of operation, wherein communicating with the first device includes: encoding data in a sequence of symbols where clock information is encoded in transitions between consecutive pairs of symbols in the sequence of symbols; inserting an extra symbol between two symbols in the sequence of symbols when transmission of the two symbols without the extra symbol would cause an undesired signaling condition on the serial bus, and transmission of the two symbols with the extra symbol would prevent the undesired signaling condition on the serial bus; and transmitting the sequence of symbols on the serial bus; and wherein a second device ignores communications on the serial bus while the serial bus is operated in the second mode of operation when the extra symbol is inserted between the two symbols. transmitting a first command to a plurality of devices coupled to a serial bus while the serial bus is operated in a first mode of operation, wherein the first command is transmitted in accordance with a first protocol to cause the serial bus to be operated in a second mode of operation; communicating with a first device of the plurality of devices in accordance with a second protocol while the serial bus is operated in the second mode of operation; and transmitting a second command to the plurality of devices in accordance with the first protocol to terminate the second mode of operation, wherein communicating with the first device includes: encoding data in a sequence of symbols where clock information is encoded in transitions between consecutive pairs of symbols in the sequence of symbols; inserting an extra symbol between two symbols in the sequence of symbols when transmission of the two symbols without the extra symbol would cause an undesired signaling condition on the serial bus, and transmission of the two symbols with the extra symbol would prevent the undesired signaling condition on the serial bus; and transmitting the sequence of symbols on the serial bus; and encoding data in a sequence of symbols where clock information is encoded in transitions between consecutive pairs of symbols in the sequence of symbols; inserting an extra symbol between two symbols in the sequence of symbols when transmission of the two symbols without the extra symbol would cause an undesired signaling condition on the serial bus, and transmission of the two symbols with the extra symbol would prevent the undesired signaling condition on the serial bus; and transmitting the sequence of symbols on the serial bus; and wherein a second device ignores communications on the serial bus while the serial bus is operated in the second mode of operation when the extra symbol is inserted between the two symbols.