100600B
Conexant
3-1
3
3.0 Electrical Interfaces
3.1 Input Interface
3.1.1 Analog Signal Selection
The Fusion 878A contains an on-chip 4:1 multiplexer (MUX[3:0]) that can be
used to switch between four composite sources or three composite sources and
one S-Video source. In the first configuration, connect the inputs of the MUX to
the four composite sources. In the second configuration, connect three inputs to
the composite sources and the other input to the luma component of the S-Video
connector. When an S-Video source is input to the Fusion 878A, the luma
component feeds through the input analog multiplexer, and the chroma
component feeds directly into the C input pin. An automatic gain control circuit
enables the Fusion 878A to compensate for nonstandard amplitudes in the analog
signal input.
illustrates the Fusion 878A’s typical external circuitry.