psb21391 Infineon Technologies Corporation, psb21391 Datasheet - Page 119

• Manufacturer Part Number: psb21391
• Description: Siemens Codec With Upn Transceiver
• Manufacturer: Infineon Technologies Corporation

4.2
The signal processor (DSP) has been conceived to perform all ITU-T and ETSI (NET33)
recommended filtering in transmit and receive paths and is therefore fully compatible to
the ITU-T G.712 and ETSI (NET33) specifications. The data processed by the DSP is
provided in the transmit direction by an oversampling A/D-converter situated in the
analog front end (AFE). Once processed, the speech signal is converted into an 8-bit A-
law or -law PCM format or remains as a 16-bit linear word (2s complement) if the
compression stage is bypassed. In the receive direction, the incoming PCM data is
expanded into a linear format (if the linear mode is selected, the expansion logic is
bypassed) and subsequently processed until it is passed to the oversampling D/A-
converter.
Additionally to these standard codec functions an universal tone generation unit and a
high quality speakerphone function (only SCOUT-PX) is provided. Figure 62 shows the
processor signal flow graph which illustrates the following description of the signal
processing in receive and transmit direction, the tone generation and speakerphone
function.
Data Sheet
Signal Processor (DSP) Description
109
PSB 21391
PSB 21393
2001-03-07
Codec