T8531TLDB Agere Systems, Inc., T8531TLDB Datasheet - Page 5

• Manufacturer Part Number: T8531TLDB
• Description: CODEC, AMuLaw CODEC, Line Card Signal Processor for CODEC Chip Set, 64TQFP
• Manufacturer: Agere Systems, Inc.

February 2002
Agere Systems Inc.
General Description
T8531 Description
As shown in Figure 4, the T8531 contains a digital signal processor (DSP) engine surrounded by a customized
input/output frame. The I/O frame performs the -law or A-law conversion as well as the decimation and interpola-
tion functions needed to interface the sigma-delta bit streams to the digital signal processor engine. The sigma-
delta converters operate at a 1.024 MHz sample rate, while the signal processor operates at 16 ksamples/s. A key
function of the I/O frame is to control the timing of the digital data going to the signal processor so that group delay
is minimized.
The I/O frame also contains an integrated phase-locked loop which synthesizes all the required internal clocks for
the chip set.
The microcontroller interface is used to run the ROM routines and to download the gain, filter, and balance network
settings, powerup/powerdown commands, time-slot assignments, digital loopback settings, and commands for the
T8532 octal chips.
JTAG
HDS
T8532 OVERSAMPLED INTERFACE
DECIMATOR
SYNTHESIZER
CLOCK
PLL
(continued)
OSDX/R[3:0]
PROCESSING
DIGITAL
ENGINE
SIGNAL
Figure 4. T8531 Block Diagram
SYSTEM PCM INTERFACE
INTERPOLATOR
DATA TRANSFER
/A-LAW CONVERTER
ROM
RAM
DSP
DSP
T8532 CONTROL INTERFACE
PROCESSOR
INTERFACE
CONTROL
MICRO-
TSA
Codec Chip Set
UPCS
UPCK
UPDI
UPDO
HIGHZB
RSTB
T_SYNC
TSTCLK
TEST
V
V
DD
SS
0505 (F)
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