TXC-04252AIPQ Transwitch Corporation, TXC-04252AIPQ Datasheet - Page 66

• Manufacturer Part Number: TXC-04252AIPQ
• Manufacturer: Transwitch Corporation

Specifications of TXC-04252AIPQ

• Pin Count: 160
• Screening Level: Industrial
• Package Type: PQFP
• Lead Free Status / Rohs Status: Not Compliant

Ed. 3, December 2000
QE1M
TXC-04252
TXC-04252-MB
The definitions (ITU-T) shown below will be used in the following discussion of the J2 16-byte message com-
parison function. The memory locations apply to each memory group.
The J2 16-byte message comparison works according to the following steps:
1. The microprocessor-written reference message (ExTI) locations should be initialized with the correct J2
2. The J2 message comparison function is then enabled (J2nCOM = 1; J2nSIZE = 0) and immediately the J2
3. The incoming trace message (RxTI) is received, and the J2 comparison circuit searches for the J2 align-
4. J2 alignment pattern is found and the Received stable trace message (AcTI) locations are updated with
5. The incoming trace message (RxTI) is then checked for three consecutive 16-byte message repeats.
6. If an error occurs before step 5 is completed, the sequence repeats, starting at step 3 (searching for the
7. If the incoming trace message (RxTI) repeats three times in a row (after the alignment pattern is detected)
8. Once the incoming trace message is in-lock, the stable message (AcTI), is compared against the micropro-
10. If the incoming message (RxTI) changes for three consecutive 16-byte messages, a loss of lock alarm
Summary of J2 Alarms:
RxTI - Received TTI (Trail Trace Identifier)
ExTI - Expected TTI (Trail Trace Identifier)
AcTI - Accepted TTI (Trail Trace Identifier)
- J2 Loss of Lock (J2nLOL) is a comparison between the Received stable message (AcTI) and the
- Declare Lock (J2nLOL = 0) when AcTI = RxTI for 3 consecutive set of 16 bytes.
- Loss of Lock (J2nLOL = 1) when AcTI
- J2 Trace Identifier Mismatch (J2nTIM) is a comparison between the Received stable message
- Declare Mismatch (J2nTIM = 1) when AcTI
16-byte message before enabling the J2 message comparison function.
Loss of Lock alarm will be active (J2nLOL = 1) and the J2 Trace Identifier Mismatch alarm will be inactive
(J2nTIM = 0). This is the first step in the sequence - to initialize these alarms.
ment pattern (Bit 1: 1000...0 pattern).
this incoming trace message (RxTI).
alignment pattern).
without an error then this is an in-lock condition, and the J2 Loss of Lock alarm is reset (J2nLOL = 0). Note
that at this time the J2 mismatch alarm is still inactive (J2nTIM =0).
cessor-written reference message (ExTI), byte for byte, for 16 bytes (the length of the multiframe mes-
sage). If they compare (AcTI = ExTI), a match is declared, with no mismatch alarm (J2nTIM = 0). If they do
not compare (AcTI
RDI and receive line AIS being sent continuously, when enabled. There is no Loss of Lock alarm (J2nLOL
= 0) because the incoming trace message (RxTI) is stable.
(J2nLOL = 1) occurs and the sequence starts again from the beginning (step 2).
Receive incoming (real time) message (RxTI).
messages
(AcTI) and the microprocessor-written reference message (ExTI).
ITU-T Definitions
Proprietary TranSwitch Corporation Information for use Solely by its Customers.
ExTI), a mismatch alarm is declared (J2nTIM = 1). A J2 mismatch alarm results in
DATA SHEET
Microprocessor-written trace (reference) message. A Side (X50H - X5FH)
RxTI on at least 1 byte in each of 3 consecutive 16-byte
- 66 of 148 -
Received stable trace message. A Side (X40H - X4FH)
ExTI on any byte once lock is declared.
Incoming J2 trace message (Real Time)
E1Mx16 Definitions
B Side (XC0H - XCFH)
B Side (XD0H - XDFH)