TXC-04252AIPQ Transwitch Corporation, TXC-04252AIPQ Datasheet - Page 59

• 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

TU/VT POINTER TRACKING
The starting location of the V1 byte is determined by either the V1 pulses in the A/BC1J1V1 signals or the H4
multiframe detection circuits. The TU/VT pointer bit assignment for the V1 and V2 bytes is shown below. The
alignment is necessary to determine the starting locations of the V5 byte and the other bytes that are carrying
the 2048 kbit/s format.
I = Increment Bit
D = Decrement Bit
N = New Data Flag Bit
Negative Justification: Inverted 5 D-bits and accept majority rule
Positive Justification: Inverted 5 I-bits and accept majority rule
SS-bits (VT Size) = 10 for 2048 kbit/s
The pointer value is a binary number with a range of 0 to 139 for the 2048 kbit/s format. The pointer offset indi-
cates the offset from the V2 byte to the first byte in the TU-12/VT2 mapping. The pointer bytes are not counted
in the offset calculation. The pointer offset arrangement for this format is shown below.
(enabled = 1001 or 0001/1101/1011/1000, normal or disabled = 0110 or 1110/0010/0100/0111)
N
1
N
Proprietary TranSwitch Corporation Information for use Solely by its Customers.
2
N
3
V1 Byte
N
4
5
SS-bits
TU/VT Pointer Offset Locations
6
Pointer Bytes Bit Assignment
2048 kbit/s TU-12/VT2
7
I
DATA SHEET
- 59 of 148 -
106-138
D
8
71-103
36-68
1-33
105
139
104
V1
V2
V3
V4
34
35
69
70
0
1
I
D
2
3
I
V2 Byte
D
4
5
I
D
6
Ed. 3, December 2000
7
I
TXC-04252
TXC-04252-MB
D
8
QE1M