1.0 Pin Description
CX28331/CX28332/CX28333
1.1 Pin Assignments
Single/Dual/Triple E3/DS3/STS-1 Line Interface Unit
Table 1-1. CX2833i-1x Pin Definitions (4 of 6)
Pin #
Signal Name
Description
I/O/P
Notes
CX28331-1x CX28332-1x CX28333-1x
43
43
43
E3MODE
E3MODE
I
When the pin is set to high, it
enables the E3 mode on all
channels, instead of the DS3/STS-1
mode. This also changes the pulse
shaper to E3 mode and overrides all
LBO pins. It also changes the
encoder/decoder from B3ZS mode
to HDB3 mode.
1 = E3 mode
0 = DS3/STS-1 mode
44
—
—
—
72
29
—
72
44
LBO
LBO1
LBO2
Transmit line Ch1
build-out mode
I
Line build-out mode per channel,
based on the length of cable on the
transmit side of the cross-connect
block. This bit is overridden and the
pulse shaper is disabled (no pulse
shaping) if E3MODE = 1.
1 = Inserts line build-out into the
transmit channel. Usually used
when the transmit cable is less than
350 feet in length.
Transmit line Ch2
build-out mode
I
I
—
—
29
LBO3
Transmit line Ch3
build-out mode
0 = Line build-out bypassed (not
inserted). Usually used when the
transmit cable is greater than 350
feet in length.
56
—
—
—
74
27
—
74
56
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
—
—
27
LLOOP3
Local loopback enable
Ch3
57
—
—
—
75
26
—
75
57
RLOOP
RLOOP1
RLOOP2
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.
Remote loopback enable
Ch2
I
I
I
1 = remote loopback enabled
0 = remote loopback disabled
—
—
26
RLOOP3
Remote loopback enable
Ch3
45
—
—
—
71
30
—
71
45
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
—
—
30
XOE3
Transmit output enable
Ch3
1-8
Conexant
100985A
CONEXANT [ CONEXANT SYSTEMS, INC ]
