TXC-04222-AIOG Transwitch Corporation, TXC-04222-AIOG Datasheet - Page 62

• Manufacturer Part Number: TXC-04222-AIOG
• Manufacturer: Transwitch Corporation

Specifications of TXC-04222-AIOG

• Screening Level: Industrial
• Package Type: BGA
• Lead Free Status / Rohs Status: Not Compliant

June 2003
TEMx28
TXC-04222
TXC-04222-MB, Ed. 6
When the H4 multiframe detector is enabled, an Out-Of-Multiframe alarm (AxHOOM and BxHOOM) is
declared when an error is detected in bits 7 and 8 of the H4 byte (where x is 1, 2, or 3 for each of the STS-1
signals in an STS-3 or 1 for the STM-1 VC-4 format). Recovery occurs when an error free H4 byte sequence is
detected in four consecutive frames (beginning with the detection of the 00 code).
Once in the OOM state, if recovery does not take place within 1 ms, an Out-Of-Multiframe alarm (AxHLOM and
BxHLOM) is declared (where x is 1, 2, or 3 for each of the STS-1 signals in an STS-3 or 1 for the STM-1 VC-4
format). Recovery occurs upon recovering of the AxHOOM or BxHOOM alarm.
SDH/SONET AIS DETECTION
The TEMx28 can detect an upstream SONET/SDH AIS condition using either the H1/H2 pointer bytes or the
E1 order wire byte. The selection is according to the following table.
Note: VT/TU AIS is detected by each of the pointer tracking state machines independently of the SONET/SDH
H1/H2 or E1 byte AIS detection circuitry.
When the control bit STS3 (bit1, 01AH) selects the VC-4/TUG-3 format, the H1 and H2 bytes or the E1 byte
per A and B drop buses are monitored for AIS. When the STS3 control bit selects the STS-3 or AU-3 format,
each set of the three H1/H2 bytes or the E1n bytes per A Drop and B Drop buses are monitored for an AIS indi-
cation. Each of the three H1/H2 pointer bytes or E1n bytes corresponds to the like-numbered AU-3/STS-1 sig-
nal (n=1-3).
When the H1/H2 bytes are selected and if all ones are detected in the H1/H2 bytes in the A drop bus for three
consecutive frames, the alarm bits AxUAIS will set, where x is equal to 1, 2, or 3, which corresponds to the like
numbered STS-1. For a VC-4 format, x is equal to 1 only. If all ones are detected in the H1/H2 bytes in the B
drop bus for three consecutive frames, the alarm bits BxUAIS will set. Recovery occurs when a normal NDF
(bits 1 through 4) in H1 is detected for three consecutive frames.
When the E1n bytes are monitored for an upstream AIS condition majority logic is used to determine if an E1n
byte is carrying an upstream AIS indication. If five or more ones are detected in an A/B Drop bus E1n byte, the
alarm bit AxUAIS or BxUAIS is set. Recovery occurs when four or less ones are detected in the byte.
(bit 0, 01DH)
HEAISE
0
1
1
Proprietary TranSwitch Corporation Information for use Solely by its Customers
(bit 1, 01DH)
SE1AIS
X
0
1
DATA SHEET
No upstream AIS monitoring performed.
The H1/H2 bytes are monitored for upstream AIS.
The E1 byte is monitored for upstream AIS.
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