ST70235A STMicroelectronics, ST70235A Datasheet - Page 10

• Manufacturer Part Number: ST70235A
• Description: Transceiver 144-Pin TQFP
• Manufacturer: STMicroelectronics

Specifications of ST70235A

• Package: 144TQFP
• Power Supply Type: Analog
• Typical Operating Supply Voltage: 1.8|3.3 V
• Minimum Operating Supply Voltage: 1.62|3 V
• Maximum Operating Supply Voltage: 1.98|3.6 V
• Case: QFP

ST70235A
Figure 3 : DSP Front-End Receive
Figure 4 : DSP Front-End Transmit
Figure 5 : DMT Modem (Rx & Tx)
This stream is still affected by carrier specific
channel distortion resulting in an attenuation of
the signal amplitude and a rotation of the signal
phase. To compensate, a Frequency domain
equalizer (FEQ) and a Rotor (phase shifter) are
implemented. The frequency domain equalization
performs an operation on the received vector in
order to match it with the associated point in the
constellation. The coefficient used to perform the
equalization are floating point, and may be
updated by hardware or software, using a
mechanism of active and inactive table to avoid
DMT synchro problems.In the transmit path, the
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To/From
DSP FE
From
DMT
Modem
From
Analog
Front-end
EQUALIZER
FILTERING
CLIPPING
IFFT
FFT
DELAY
FEQ COEFFICIENTS
SELECT
FEQ Update
IN
FEQ
FTG
POLATOR
INTER-
ROTOR
AFE
I/F
IFFT reverses the DMT symbol from frequency
domain to time domain.
The IFFT block is preceded by Fine Tune Gain
(FTG)
compensation of the possible frequency mismatch
between the master clock frequency and the
transmitter clock frequency (which may be locked
to another reference).
The Inverse Fast Fourier Transform process is
used to transform from frequency domain to time
domain (transmit path). 256 positive frequencies
are processed, giving 512 samples in the time
domain.
BYPASS
DEC
AFE
I/F
and
DEMAPPER
DECODING
MONITOR
TREILLIS
Rotor
MAPPER
CODING
Monitor Indications
TEC
SELECT
OUT
stages,
To DMT
Modem
allowing
To Analog
Front End
To/From
TC
for
a