TDA7706

Function description

Doc ID 022898 Rev 3

11/16

Figure 3.

Crystal oscillator block diagram

2.11

DSP

The TDA7706 embeds two DSP cores for high computational power and achievable

customization. The first DSP and its hardware accelerators take care of all the tuner digital

signal processing. The main program is fixed in ROM. Control parameters are copied to

RAM and they are accessible and modifiable there, thus allowing a parametric performance

optimization. The first DSP core performs:

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digital down-conversion of IF

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bandwidth selection with variable controlled bandwidth

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FM and AM noise blanking

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FM/AM demodulation with soft-mute, high-cut, weak signal processing and quality

detection

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FM stereo decoding with stereo-blend

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RDS demodulation including error correction and block synchronization with generation

of an RDS interrupt for the main µP

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Autonomous control of RDS-AF tests

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Self-alignment of pre-selection tuning

The second DSP is totally free for custom processing implementation. The second

(customizable DSP) can interact with the main DSP by tapping the signal at the access

points as shown in the Figure 4 below.