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STB Application

TSB43DA42

M6

Ex-CPUorPCII/F

Async TXFIFO

MPEG2Demux

MPEG2

TransportStream

fromSatelliteor

Cable

SDRAM

CPU

PCIor68KBus

Graphics

Controller

1394Bus

Digital Audio

61937

MPEG2

Transport

Stream

M6

TSB43DA42, TSB43DB42

SLLS560 – FEBRUARY 2007

APPLICATION INFORMATION (continued)

Figure 2. TSB43DA42 in STB Application

The set top box receives the MPEG2 transport stream from either satellite or cable sources. The MPEG2 demux

device splits the audio and video portion of the MPEG2 transport stream. The video portion, including 2-channel

audio, is input to the TSB43DA42 HSDI port. The TSB43DA42 performs any PID filtering or packet insertion,

encrypts the stream using M6 cipher, and transmits the stream over 1394.

The audio portion of the transport stream is packed into SPDIF format by the MPEG2 demux device using the

IEC61937 standard. The audio stream is input to the TSB43DA42 audio port, encrypted using M6 cipher if

necessary, and transmitted over 1394.

The set top box also creates on screen display (OSD) graphics to transmit to the sink device. The system inputs

the OSD data to the TSB43DA42 asynchronous transmit FIFO. The TSB43DA42 transmits the OSD using

asynchronous packets to the sink device.

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