XRT94L31IB Exar Corporation, XRT94L31IB Datasheet - Page 33

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

Specifications of XRT94L31IB

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

REV. 1.0.1
PIN DESCRIPTION OF THE XRT94L31 (REV. B)
PIN #
AF18
D17
A9
TxOHFRAME_0
TxOHFRAME_1
TxOHFRAME_2
SIGNAL NAME
I/O
O
CMOS
TYPE
Transmit Overhead Framing Pulse:
This input pin functions as the Transmit Overhead Framing Pulse for the
transmit system side interface when the XRT94L31 is configured to
operate in DS3/E3 mode, however, it functions as the Transmit STS-1
Overhead Enable output when the device is configured to operate in the
STS-1 mode.
When configured to operate in DS3/E3 mode:
This output pin pulses "High" (for one TxOHClk_n period) coincident with
the instant that the DS3/E3 Frame Generator block will be accepting the
very first overhead bit within an outbound DS3 or E3 frame (via Transmit
Overhead Data Input Interface).
When configured to operate in STS-1 mode:
These output pins, along with the TxOH_n, TxOHEnable_n, TxOHIns_n
and TxOHClk_n function as the Transmit Overhead Input Port.The func-
tion of these output pins depends upon whether or not the user inserting
POH or TOH data via the TxOH_n input pins.
If the user is only inserting POH data via these input pins:
In this mode, the TxOH port will pulse these output pins "High" whenever
it is ready to accept and process the J1 byte (e.g., the very first POH
byte) via this port.
If the user is inserting both POH and TOH data via these input pins:
In this mode, the TxOH port will pulse these output pins "High" coinci-
dent with the following.
Whenever the TxOH port is ready to accept and process the A1 byte
(e.g., the very first TOH byte) via this port.
Whenever the TxOH port is ready to accept and process the J1 byte
(e.g., the very first POH byte) via this port.
N
OTES
1. The externally circuitry can determine whether or not the TxOH
2. If the TxOHEnable_n output pin is "High" while the
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC
:
port is expecting the A1 byte or the J1 byte, by checking the
state of the corresponding TxOHEnable output pin. If the
TxOHEnable_n output pin is "Low" while the TxOHFrame_n
output pin is "High", then the TxOH port is ready to process the
A1 (TOH) bytes.
TxOHFrame_n output pin is "High", then the TxOH port is ready
to process the J1 (POH) bytes.
33
DESCRIPTION
XRT94L31