1.0 Pin Description
CX28331/CX28332/CX28333
1.1 Pin Assignments
Single/Dual/Triple E3/DS3/STS-1 Line Interface Unit
Table 1-2. CX2833i-3x Pin Definitions (5 of 8)
Pin #
Signal Name
Description
I/O/P
Notes
CX28331-3x CX28332-3x CX28333-3x
71
—
—
—
93
32
—
93
71
LLOOP
LLOOP1
LLOOP2
Local loopback
enable Ch1
I
Local loopback enable per channel. The
transmit data is looped back immediately
from the encoder to the decoder in place of
the received data.
Local loopback
enable Ch2
I
I
I
1 = local loopback enabled
0 = local loopback disabled
—
—
32
LLOOP3
Local loopback
enable Ch3
72
—
—
RLOOP
Remote
loopback enable
Ch1
Remote loopback enable per channel. The
receive data, retimed after clock recovery, is
looped back into the AMI generator in place
of the transmit data.
—
94
94
RLOOP1
—
—
31
72
31
RLOOP2
RLOOP3
Remote
loopback enable
Ch2
I
I
I
1 = remote loopback enabled
0 = remote loopback disabled
—
Remote
loopback enable
Ch3
56
—
—
—
90
35
—
90
56
XOE
XOE1
XOE2
Transmit output
enable Ch1
Transmit output enable per channel.
1 = transmit line output driver enabled
0 = transmit output driver set to high
impedance state
Transmit output
enable Ch2
I
I
I
—
—
35
XOE3
Transmit output
enable Ch3
57
—
—
REQH
Ch1 Receive
High EQ Gain
Enable
The equalizer in the CX2833i has two gain
settings. The higher gain setting is designed
to optimally equalize a nominally-shaped
(meets the pulse template), pulse-driven
DS3 or STS-1 waveform that is driven
through 0–900 feet of cable.
Square-shaped pulses such as E3 or
DS3-HIGH require less high-frequency gain
and should use the low EQ gain setting.
—
89
89
REQH1
—
36
57
REQH2
Ch2 Receive
High EQ Gain
Enable
I
I
—
—
36
REQH3
Ch3 Receive
High EQ Gain
Enable
REQH = 1 high EQ gain (DS3/STS-1 modes)
REQH = 0 low EQ gain (E3/DS3
Square Modes)
Power/Ground
15
—
5
—
5
TVDD
TVDD1
TVDD2
TVDD3
TX power Ch1
P
Power pins for transmit circuitry per
channel (3.3 V).
—
—
25
—
15
25
TX power Ch2
TX power Ch3
P
P
1-18
Conexant
100985A
CONEXANT [ CONEXANT SYSTEMS, INC ]
