XRT94L31IB-L Exar Corporation, XRT94L31IB-L Datasheet - Page 70

• Manufacturer Part Number: XRT94L31IB-L
• Description: IC MAPPER DS3/E3/STS-1 504TBGA
• Manufacturer: Exar Corporation

Specifications of XRT94L31IB-L

• Applications: Network Switches
• Interface: Bus
• Voltage - Supply: 3.14 V ~ 3.47 V
• Package / Case: 504-LBGA
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

XRT94L31
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC
PIN DESCRIPTION OF THE XRT94L31 (REV. B)
24AG
PIN #
AC13
A14D
20AE
A15B
N27
A16
J23
14
14
RxOOF_0RxOOF_1R
RxLOS_0RxLOS_1R
RXUCLK/RXPCLK
SIGNAL NAME
EXTLOS_0
EXTLOS_1
EXTLOS_2
xOOF_2
xLOS_2
I/O
O
O
I
I
TTL
TTL
CMOS
CMOS
TYPE
For mapper applications, Please connect this pin to GND
Receive LOS (Loss of Signal) Indicator Input (from an off-chip DS3/
E3/STS-1 LIU IC):
These input pins are intended to be connected to a corresponding RLOS
(Receive Loss of Signal) output pin of an off-chip DS3/E3/STS-1 LIU IC.
Through this connection, if a given LIU Channel declares the LOS defect
condition, it will (in-turn) drive the corresponding EXTLOS_n input pin (to
the XRT94L31) to the logic "High" level.
If the a given channel (within the XRT94L31) is configured to operate in
either the DS3 or E3 Mode, and if the off-chip LIU IC asserts the corre-
sponding EXTLOS_n input pin (by driving it to the logic "High" level),
then the DS3/E3 Framer block (within this particular channel) will auto-
matically declare the LOS defect condition (for the duration that this
input pin is driven to a logic "High".
If the LIU Channel toggles this input pin "Low", then the corresponding
DS3/E3 Framer block (within the XRT94L31) will MOST LIKELY clear
the LOS defect condition.
N
Receive STS-1/DS3/E3 Out of Frame IndicatorThe STS-1/DS3/E3
Receive DS3 Framer will assert this output signal whenever it has
declared an Out of Frame (OOF) condition with the incoming DS3
frames. This signal is negated when the framer correctly locates the F-
and M-bits and regains synchronization with the DS3 frame.
STS-1/DS3/E3 Framer - Loss of Signal Output Indicator:
This pin is asserted when the Receive Section of the channel encoun-
ters 180 consecutive 0's (for DS3 applications) or 32 consecutive 0's (for
E3 applications) via the RxPOS_n and RxNEG pins. For STS-1 applica-
tions, users can set the LOS threshold value in the Receive LOS Thresh-
old register. (RxSTOH_LOS_TH, Address Location: 0xN02E - 0xN02F)
This pin will be negated once the Receive DS3/E3 Framer has detected
at least 60 1s out of 180 consecutive bits (for DS3 applications) or has
detected at least four consecutive 32 bit strings of data that contain at
least 8 1s in the receive path.
OTES
1. The DS3/E3 Framer block can be configured to declare and
2. These input pins are ignored if their corresponding Channel
:
clear the LOS defect condition based upon both the state of this
input pin and the content within the incoming DS3/E3 data-
stream.
UNCONDITIONALLY declare the LOS defect condition, if its
corresponding EXTLOS_n input pin is driven to the logic "High"
level.
has been configured to operate in the STS-1 Mode.
Receive STS-1 TOH Processor block will only declare and
clear the LOS defect condition based the number of
consecutive All Zero bytes that are detected within the
incoming STS-1 data-stream.
70
However,
DESCRIPTION
the
DS3/E3
Framer
block
REV. 1.0.1
The
will