T8531A/T8532 Agere Systems, Inc., T8531A/T8532 Datasheet - Page 23

• Manufacturer Part Number: T8531A/T8532
• Description: Multichannel Programmable Codec Chip Set
• Manufacturer: Agere Systems, Inc.

May 2001
Chip Set Functional Description
(continued)
Self-Test and Line-Test Routines
(continued)
Tone Detection
In tone detection mode, the TX part of the channel can
be used to detect signal energy from the line at a given
frequency up to 4 kHz. This routine performs discrete
Fourier transform (DFT) to capture and analyze the
reflected tone. The routine does not employ the trans-
mit bandpass filters. The number of frames to sample
the reflected tone must be defined. The number of
frames that DFT is run must be a power of 2 and
should be complete cycles of tone value.
dc Generation
This routine generates a dc signal (value defined by
user) in the RX path.
dc Measurement
Provides average dc value and difference between two
average values.
Variance Computation
The variance routine computes the variance of small
noise signals from the TX path around the computed
mean level. This routine employs the transmit band-
pass filters for out-of-band noise reduction.
Peak Detection
This routine examines the incoming TX signal and
saves the maximum and minimum signal values. Two
versions are provided. The peak detection routine
scales the result by the TX absolute gain. The alternate
peak detection routine does not.
Agere Systems Inc.
T8531A Tone Processing manual for more information
Tone Plant
The following tone plant functions are provided in ROM
code in the T8531A device. Refer to the T8531 and
DTMF Transceiver
DTMF generation and detection satisfies LSSGR Sig-
naling for Analog Interfaces GR-506 CORE, section
15.
Caller Line Identification
Called ID transmission is performed as specified in TR-
NWT-000031 (CLASS feature: calling number deliv-
ery).
Call Progress Tones
A call progress tone generator is provided. This tone
generator complies with Telcordia * GR-506-CORE
requirements.
* Telcordia is a trademark of Telcordia Technologies, Inc.
Codec Chip Set
23