psb21391 Infineon Technologies Corporation, psb21391 Datasheet - Page 124

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

Data Sheet
4.3
The ASP contains a universal tone generator which can be used for tone alerting, call
progress tones, DTMF-signals or other audible feedback tones.
All the tone generation configurations are programmable in the registers TGCR (Tone
Generator Configuration Register) and TGSR (Tone Generator Switch Register) and the
CRAM parameters.
The tone generation unit consists of following main blocks:
• Four Signal Generators
• Sequence Generator
• Control Generator
• Tone Filter
• Tone Level Adjustment
Figure 64 shows the signal flow graph of the tone generation unit and illustrates the
following functional description.
4.3.1
The four signal generators can be programmed by CRAM parameters in frequency
(Fn,FD) and gain (Gn,GDn). For the signal generators F1,F2,F3 a trapezoid or square
waveform can be selected by setting the TGCR.SQTR bit. The signal generator FD has
a trapezoid waveform.
The signal generators in conjunction with the tone sequence generator and the control
generator allow to generate different multitone patterns without reprogramming the
necessary parameters.
4.3.2
The sequence generator can be enabled or disabled by setting the TGCR.SEQ
(Sequence Generator) bit. If the sequence generator is enabled depending on the
TGCR.TM (Tone Mode) bit two or three tone sequences of the signals (F1, G1), (F2,G2)
and (F3,G3) are generated. The CRAM parameters T1, T2, T3 determine the duration of
these individual signals.
If the sequence generator is disabled a continuous tone is generated. The selected
signal generator depends on the TGCR.TM (Tone Mode) bit.
By setting the TGSR.DT (Dual Tone Mode) bit the output of the signal generator FD (FD,
GDn) can be added to the tone signal which is determined by the SEQ and TM bit.
Note: The dual tone mode and the three tone sequence can only be used if the DTMF
Table 12 shows the programmable CRAM Parameters of the tone and sequence
generator.
In Table 13 possible tone signals are listed which can be realized with the control bits
SEQ, TM and DT.
mode is disabled (TGSR.DTMF = ’0’)
Tone Generation
Four Signal Generators
Sequence Generator
114
PSB 21391
PSB 21393
2001-03-07
Codec