Datasheet

LM49350, LM49350RLEVAL
www.ti.com SNAS359D –SEPTEMBER 2008–REVISED JUNE 2012
Digital Mixer Control Registers
DIGITAL MIXER
The LM49350’s digital mixer allows for flexible routing of digital audio signals between both audio ports, DAC,
and ADC. This mixer handles which digital data path (Port1 RX data, Port2 RX data, or ADC output) is routed to
the DAC input. The digital mixer also selects the appropriate digital data path [Port1 RX data, Port2 RX data,
ADC output, or DAC DSP (Interpolator)] output that is used for data transmission on Audio Port 1 and 2. Audio
inputs to the digital mixer can be attenuated down to -18dB to avoid clipping conditions. The digital mixer also
allows direct routing from the DAC interpolator output to the ADC decimator input which allows the DAC and
ADC DSP blocks to be cascaded without having to enable the analog of the DAC and ADC inorder to save
power.
Another key feature of the digital mixer is sample rate conversion (SRC) between audio ports. This allows
simultaneous operation of the dual audio ports even if each port is operating at a different sample rate. The
LM49350 can be used as an audio port bridge with SRC capability. The digital mixer allows either straight pass
through between audio ports or, if desired, DSP effects can be added to the digital audio signal during audio port
bridge operation. The digital mixer automatically handles stereo I
2
S to mono PCM conversion between audio
ports and vice versa.
Figure 58. Digital Mixer
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