Apparatus and methods for serial interfaces with shared datapaths

A serial interface comprising:

• a plurality of lower-speed physical media attachment channels, each lower-speed physical media attachment channel including a lower-speed serializer-deserializer (SERDES) circuit and lower-speed non-SERDES circuitry which includes a lower-speed clock data recovery circuit;
• a higher-speed physical media attachment channel including higher-speed non-SERDES circuitry which includes a higher-speed clock data recovery circuit;
• and
• a plurality of multiplexers arranged to connect a lower-speed SERDES circuits to a lower-speed non-SERDES circuitry in each lower-speed physical media attachment channel in a first configuration and to connect the plurality of lower-speed SERDES circuits to the higher-speed physical media attachment channel in a second configuration.

A method of providing a serial interface on an integrated circuit, the method comprising:

• receiving two sub-groups of parallel transmission data streams by two lower-speed physical coding sublayer channels;
• encoding the two sub-groups of parallel transmission data streams by the two lower-speed physical coding sublayer channels to form two sub-groups of encoded data streams;
• sending the two sub-groups of encoded data streams in parallel to a higher-speed serializer circuit;
• and
• serializing the two sub-groups of encoded data by the higher-speed serializer circuit to form a higher-speed serial transmission data stream.

A method of providing a serial interface on an integrated circuit, the method comprising:

• receiving two sub-groups of parallel transmission data streams by two lower-speed physical coding sublayer channels;
• encoding the two sub-groups of parallel transmission data streams by the two lower-speed physical coding sublayer channels to form two sub-groups of encoded data streams;
• serializing the two sub-groups of encoded data streams by two lower-speed serializer circuits to create two lower-speed serial transmission data streams;
• and
• serializing the two lower-speed serial transmission data streams to form a higher-speed serial transmission data stream.