XRT59L91 Datasheet, PDF (3/28 Pages) Exar Corporation – Single-Chip E1 Line Interface Unit

Preliminary
XRT59L91
PIN CONFIGURATION
T x C lk
1
TxPOS
TxNEG
LLoop
RLoop
RxPOS
RxNEG
RxLOS
8
16
TVSS
T R in g
TVDD
TTIP
RVDD
RVSS
R R in g
9
R T IP
PIN DESCRIPTION
Pin#
1
2
Symbol
TxClk
TxPOS
Type
I
Description
Transmitter Clock Input:
If the user operates the LIU in the “clocked” mode, then the “Transmit
Section” of the LIU will use the falling edge of this signal to sample the
data at the TxPOS and TxNEG input pins.
Note: If the user operates the LIU in the “clockless” mode, then the
Terminal Equipment should not apply a clock signal to this input pin.
I
Transmit – Positive Data Input:
The exact signal that should be applied to this input pin depends upon
whether the user intends to operate the “Transmit Section” (of the device)
in the “Clocked” or “Clockless” Mode.
Clocked Mode -
The Terminal Equipment should apply bit-wide NRZ pulses on this input
pin, whenever the Terminal Equipment needs to transmit a “positive-
polarity” pulse onto the line via TTIP and TRing output pins. The
XRT59L91 device will sample this input pin upon the falling edge of the
TCLK signal.
Clockless Mode -
The Terminal Equipment should apply RZ pulses to this input pin,
anytime the Terminal Equipment needs to transmit a “positive-polarity”
pulse onto the line via TTIP and TRing output pins.
Rev. P2.00
3