DS3171/DS3172/DS3173/DS3174
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8.2 Detailed Pin Descriptions
Table 8-2. Detailed Pin Descriptions
n=1,2,3,4 (port number); Ipu (input with pullup), Oz (output tri-stateable) (needs an external pullup or pulldown resistor to keep from floating), Oa
(Analog output), Ia (analog input), IO (Bidirectional inout); all unused input pins without pullup should be tied low.
PIN NAME
TYPE
PIN DESCRIPTION
Line IO
TLCLKn
O
Transmit Line Clock Output
TLCLKn
: This signal is available when the transmit line interface pins are enabled
(
PORT.CR2.
TLEN). This clock is typically used as the clock reference for the TDATn
and TNEG signals, but can also be used as the reference for the TSOFIn, TSERn,
and TSOFOn / TDENn signals.
This output signal can be inverted.
o
DS3: 44.736 MHz +20 ppm
o
E3: 34.368 MHz +20 ppm
Transmit Positive AMI / Data Output
TPOSn
: When the port line interface is configured for B3ZS, HDB3 or AMI mode and
the transmit line interface pins are enabled (
PORT.CR2.
TLEN), a high on this pin
indicates that a positive pulse should be transmitted on the line. The signal is updated
on the positive clock edge of the referenced clock pin if the clock pin signal is not
inverted, otherwise it is updated on the falling edge of the clock. The signal is typically
referenced to the TLCLKn line clock output pins, but it can be referenced to the
TCLKOn, TCLKIn, RLCLKn or RCLKOn pins. This output signal can be disabled
when the TX LIU is enabled.
This output signal can be inverted.
TDATn
: When the port line interface is configured for UNI mode and the transmit line
interface pins are enabled (
PORT.CR2.
TLEN), the un-encoded transmit signal is
output on this pin. The signal is updated on the positive clock edge of the referenced
clock pin if the clock pin signal is not inverted, otherwise it is updated on the falling
edge of the clock. The signal is typically referenced to the TLCLK line clock output
pins, but it can be referenced to the TCLKOn, TCLKIn, RLCLKn or RCLKOn pins
This output signal can be inverted.
o
DS3: 44.736 Mbps +20ppm
o
E3: 34.368 Mbps +20ppm
Transmit Negative AMI / Line OH Mask
TNEGn
: When the port line is configured for B3ZS, HDB3 or AMI mode and the
transmit line interface pins are enabled (
PORT.CR2.
TLEN), a high on this pin
indicates that a negative pulse should be transmitted on the line. The signal is
updated on the positive clock edge of the referenced clock pin if the clock pin signal is
not inverted, otherwise it is updated on the falling edge of the clock. The signal is
typically referenced to the TLCLKn line clock output pins, but it can be referenced to
the TCLKOn, TCLKIn, RLCLKn or RCLKOn pins.
This output signal can be inverted.
o
DS3: 44.736 Mbps +20ppm
o
E3: 34.368 Mbps +20ppm
Transmit Positive Analog
TXPn
: This pin and the TXNn pin form a differential AMI output which is coupled to
the outbound 75 coaxial cable through a 2:1 step-down transformer (
Figure 1-1
).
This output is enabled when the TX LIU is enabled and the output is enabled to be
driven. When it is not enabled, it is in a high impedance state.
o
DS3: 44.736 Mbps +20ppm
o
E3: 34.368 Mbps +20ppm
Transmit Negative Analog
TXNn
: This pin and the TXPn pin form a differential AMI output which is coupled to
the outbound 75 coaxial cable through a 2:1 step-down transformer (
Figure 1-1
).
TPOSn /
TDATn
O
TNEGn
O
TXPn
Oa
TXNn
Oa