
XRT72L54
á
FOUR CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.2
PRELIMINARY
23
T1
RLOL[2]
I
See Description for Pin B8
T2
ExtLOS[3]
I
See Description for Pin D9
T3
RxOOF[2]
O
See Description for Pin A3
T4
RxAIS[3]
O
See Description for Pin C5
T17
RxClk[2]
O
See Description for Pin D20
T18
NibbleIntf
I
Nibble Interface Select Input Pin:
This input pin allows the user to configure the Transmit Payload Data
Input Interface and the Receive Payload Data Output Interface to oper-
ate in either the "Serial-Mode" or the "Nibble/Parallel-Mode".
Setting this input pin "high" configures the Transmit and Receive Termi-
nal Interfaces to operate in the "Nibble/Parallel-Mode". In this mode, the
“Transmit Payload Data Input Interface” block will accept the “outbound”
payload data (from the 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 the “inbound” payload data (to the
Terminal Equipment) in a “nibble-parallel” manner via the “RxNib[3:0]”
output pin.
Setting this input pin "low" configures the Transmit and Receive Termi-
nal Interfaces to operate in the "Serial" Mode. In this mode, the “Trans-
mit Payload Data Input Interface” block will accept the “outbound”
payload data (from the 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 Terminal Equipment)
in a “serial” manner via the “RxSer” output pin.
T19
Reset
I
Reset Input:
When this "active-low" signal is asserted, the Framer device will be
asynchronously reset. Additionally, all outputs will be "tri-stated", and all
on-chip registers will be reset to their default values.
T20
MOTO
I
Motorola/Intel Processor Interface Select Mode:
This input pin allows the user to configure the Microprocessor Interface
to interface with either a "Motorola-type" or "Intel-type" microprocessor/
microcontroller. Tying this input pin to VCC, configures the microproces-
sor interface to operate in the Motorola mode (e.g., the Framer device
can be readily interfaced to a "Motorola type" local microprocessor).
Tying this input pin to GND configures the Microprocessor Interface to
operate in the Intel Mode (e.g., the Framer device can be readily inter-
faced to a “Intel type" local microprocessor).
U1
RxOOF[3]
O
See Description for Pin A3
U2
RxLOS[3]
O
See Description for Pin C4
U3
RxAIS[2]
O
See Description for Pin C5
U4
GND
****
Ground
U5
RLOOP[2]
O
See Description for Pin B7
U6
VDD
****
Power Supply +3.3v ± 5%
PIN DESCRIPTION
PIN #PIN NAME
TYPE
DESCRIPTION