
DS26521 Single T1/E1/J1 Transceiver
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7.
PIN DESCRIPTIONS
7.1
Pin Functional Description
Table 7-1. Detailed Pin Descriptions
NAME
PIN
TYPE
FUNCTION
ANALOG TRANSMIT
TTIP
6
Analog
Output,
High
Impedance
Transmit Bipolar Tip.
This pin is a differential line driver tip output. This pin can
be high impedance if:
If TXENABLE is low, the TTIP/TRING will be high impedance. Note that if
TXENABLE is low, the register settings for control of the TTIP/TRING are ignored
and output is high impedance.
The differential outputs of TTIP and TRING can provide internal matched
impedance for E1 75
Ω , E1 120Ω, T1 100Ω, or J1 110Ω. The user has the option
TRING
7
Analog
Output,
High
Impedance
Transmit Bipolar Ring.
This pin is a differential line driver ring output. This pin
can be high impedance if:
If TXENABLE is low, the TTIP/TRING will be high impedance. Note that if
TXENABLE is low, the register settings for control of the TTIP/TRING are ignored
and output is high impedance.
The differential outputs of TTIPn and TRINGn can provide internal matched
impedance for E1 75
Ω, E1 120Ω, T1 100Ω, or J1 110Ω. The user has the option of
turning off internal termination.
TXENABLE
13
I
Transmit Enable.
If this pin is pulled low, all transmitter outputs (TTIP and TRING)
are high impedance. The register settings for tri-state control of TTIP/TRING are
ignored if TXENABLE is low. If TXENABLE is high, the particular driver can be tri-
stated by the register settings.
ANALOG RECEIVE
RTIP
10
Analog
Input
Receive Bipolar Tip.
The differential inputs of RTIP and RRING can provide
internal matched impedance for E1 75
Ω, E1 120Ω, T1 100Ω, or J1 110Ω. The user
has the option of turning off internal termination via the LIU Receive Impedance
and Sensitivity Monitor register
(LRISMR).
RRING
11
Analog
Input
Receive Bipolar Ring.
The differential inputs of RTIP and RRING can provide
internal matched impedance for E1 75
Ω, E1 120Ω, T1 100Ω, or J1 110Ω. The user
has the option of turning off internal termination via the LIU Receive Impedance
and Sensitivity Monitor register
(LRISMR).
TRANSMIT FRAMER
TSER
64
I
Transmit NRZ Serial Data.
This pin is sampled on the falling edge of TCLK when
the transmit-side elastic store is disabled. This pin is sampled on the falling edge of
TSYSCLK when the transmit-side elastic store is enabled.
In IBO mode, data for multiple framers can be used in high-speed multiplexed
scheme. This is described in Section
8.8.2. The table there presents the
combination of framer data for each of the streams.
TSYSCLK is used as a reference when IBO is invoked.
TCLK
63
I
Transmit Clock.
A 1.544MHz or a 2.048MHz primary clock. Used to clock data
through the transmit side of the transceiver. TSER data is sampled on the falling
edge of TCLK. TCLK is used to sample TSER when the elastic store is not enabled
or IBO is not used.
TSYSCLK
62
I
Transmit System Clock.
1.544MHz, 2.048MHz, 4.096MHz, 8.192MHz, or
16.384MHz clock. Only used when the transmit-side elastic store function is
enabled. Should be tied low in applications that do not use the transmit-side elastic
store. The clock can be 4.096MHz, 8.912MHz, or 16.384MHz when IBO mode is
used.