Multi-stage high speed bit stream demultiplexer chip set having switchable master/slave relationship

Abstract

A bit stream demultiplexer that couples a high-speed bit stream media to a communication Application Specific Integrated Circuit (ASIC). The bit stream multiplexer performs its demultiplexing function staged within at least two integrated circuits. The first Integrated Circuit (IC) receives a first bit stream and performs a first demultiplexing function. A second IC performs a second demultiplexing function. The second IC acts as either a slave or a master to the first IC. In a slave mode, the second IC depends upon a transmit data clock from the first IC for latching bit stream data received from the first IC. When the second IC operates in the master mode, the second IC uses the transmit data clock from first IC as a reference input for a PLL to generate a Receive Data Clock. If an LOL or LOS occurs within the first IC, a signal to the second IC indicates these conditions causing the second IC to switch to a local oscillator reference clock to generate the Receive Data Clock.