XRT79L71 Datasheet, PDF (20/441 Pages) Exar Corporation – 1 - CHANNEL DS3/E3 ATM UNI/PPP COMBO IC

XRT79L71
REV. P1.0.3
PRELIMINARY
áç
1 - CHANNEL DS3/E3 ATM UNI/PPP COMBO IC
PIN #
NAME
TYPE
GENERAL PURPOSE INPUT AND OUTPUT PINS
DESCRIPTION
T8
DMO
O Drive Monitor Output Output Pin:
If this input signal is "High", then it means that the drive monitor circuitry within the
XRT79L71 has not detected any bipolar signals at the MTIP and MRING inputs
within the last 128 ± 32 bit periods. If this input signal is "Low", then it means that
bipolar signals are being detected at the MTIP and MRING input pins of the
XRT79L71.
T7
GPIO_0
I/O General Purpose Input/Output Pins:
N8
GPIO_1
P8
GPIO_2
R8
GPIO_3
Each of these pins can be configured to function as either an input or output pin.
If a given pin is configured to function as an input pin, then the state of this input
pin can be monitored by reading Bit X within the "XXX" Register (Address Loca-
tion = 0xXX, 0xXX).
If a given pin is configured to function as an output pin, then the state of these out-
put pins can be controlled by writing the appropriate value into Bit X within the
"XXX" Register.
PIN #
NAME
TYPE
TRANSMIT SYSTEM SIDE INTERFACE PINS
DESCRIPTION
A13
TxAISEn
I Transmit AIS Pattern Input pin:
This input pin is used to command the Transmit DS3/E3 Framer block to transmit
an AIS pattern to the remote terminal equipment.
Setting this input pin "High" configures the Transmit DS3/E3 Framer block to
transmit an AIS pattern to the remote terminal equipment. Setting this input pin
"Low" configures the Transmit DS3/E3 Framer block to NOT transmit an AIS pat-
tern to the remote terminal equipment.
NOTE: For normal operation, or if the user wishes to control the Transmit AIS
function, via Software Control; the user should tie this input pin to GND.
L16
NibbleIntf
I Nibble Interface Select Input pin:
This input pin is used to configure the Transmit Payload Data Input Interface and
the Receive Payload Data Output Interface blocks to operate in either the Serial
or the Nibble-Parallel Mode.
Setting this input pin "High" configures each of these blocks to operate in
the Nibble-Parallel Mode.
In this mode, the Transmit Payload Data Input Interface block will accept the out-
bound payload data from the local terminal equipment in a nibble-parallel man-
ner via the TxNib[3:0] input pins. Further, the Receive Payload Data Output
Interface block will output inbound payload data to the local terminal equipment
in a nibble-parallel via the RxNib[3:0] output pins.
Setting this input pin "Low" configures each of these blocks to operate in
the Serial Mode.
In this mode, the Transmit Payload Data Input Interface block will accept the out-
bound payload data from the local terminal equipment in a serial manner via the
TxSer input pin. Further, the Receive Payload Data Output Interface block will
output the inbound payload data to the local terminal equipment in a serial man-
ner, via the RxSer output pin.
NOTE: This input pin is only active if the XRT79L71 has been configured to
operate in the Clear-Channel Framer Mode.
8