I90135 Datasheet, PDF (5/9 Pages) List of Unclassifed Manufacturers – ADSL Digital Chip

I90135
Product Data Sheet
Version 1.2 (June 1999)
Mapper/Demapper, Monitor, Trellis
Coding, FEQ Update
The demapper converts the constellation
points computed by the FFT to a block of
bits. This essentially consists in identifying
a point in a 2D QAM constellation plane.
The demapper supports trellis coded
demodulation and provides a Viterbi
maximum likelihood estimator. When the
trellis is active, the demapper receives an
indication for the most likely constellation
subset to be used. In the transmit
direction, the mapper performs the inverse
operation, mapping a block of bits into one
Pin Diagram
constellation point (in a complex x+jy
representation) which is passed to the IFFT
block. The Trellis Encoder generates
redundant bits to improve the robustness of
the transmission, using a 4-Dimensional
Trellis Coded Modulation scheme. The
Monitor computes error parameters for
carriers specified in the Demapper process.
Those parameters can be used for updates
of adaptive filters coefficient, clock phase
adjustments, error detection, etc. A series
of values is constantly monitored, such as
signal power, pilot phase deviations, symbol
erasures generation, loss of frame, etc.
VSS
1
AD_0
2
AD_1
3
AD_2
4
VDD
5
AD_3
6
AD_4
7
VSS
8
AD_5
9
AD_6
10
VDD
11
AD_7
12
AD_8
13
AD_9
14
VSS
15
AD_10
16
AD_11
17
VDD
18
AD_12
19
VSS
20
PCLK
21
VDD
22
AD_13
23
AD_14
24
AD_15
25
VSS
26
BE1
27
ALE
28
VDD
29
CSB
30
WR_RDB
31
RDYB
32
OBC_TYPE 33
INTB
34
RESETB
35
VSS
36
OBC
AFE
TEST
SLAP
UTOPIA
108
VDD
107 SLT_REQ_F
106 SLT_DAT_S0
105 SLT_DAT_S1
104 SLT_DAT_F0
103 SLT_DAT_F1
102
VSS
101 SLT_FRAME_F
100 SLAP_CLOCK
99 SLR_VAL_F
98 SLR_DAT_F0
97 SLR_DAT_F1
96 SLR_VAL_S
95
VDD
94 SLR_DAT_S0
93 SLR_DAT_S1
92 SLR_FRAME_S
91
VSS
90 SLR_FRAME_F
89 U_TX_ADDR_0
88 U_TX_ADDR_1
87 U_TX_ADDR_2
86
VDD
85 U_TX_ADDR_3
84 U_TX_ADDR_4
83 U_TX_DATA_0
82 U_TX_DATA_1
81
VDD
80 U_TX_DATA_2
79 U_TX_DATA_3
78 U_TX_DATA_4
77 U_TX_DATA_5
76
VDD
75 U_TX_DATA_6
74 U_TX_DATA_7
73
VSS
Figure 3: Pinout (Topside View)
Integrated Telecom Express, Inc.
5