T7256 Agere Systems, T7256 Datasheet - Page 15

• Manufacturer Part Number: T7256
• Description: (T7234 - T7256) Compliance
• Manufacturer: Agere Systems

Lucent Technologies Inc.
February 1998
S/T-Interface Frame Structure
In the TE-to-NT direction, in at least four of five frames, this second violation occurs within 13 bits of the F bit. If this
coding algorithm is not maintained, the receiver loses synchronization, but the T7234 continues transmitting. Multi-
framing is not supported in the T7234.
F = Framing bit
L = dc balancing bit
D = D-channel bit
E = Echo D-channel bit
+0
–0
1
48 1
L F
2-bit OFFSET
INFO 0
INFO 2
INFO 4
D
48 1
L B1
2
L
TIME
3
F
No signal.
Frame with all bits of B, D, and D echo (E) channels set to
binary ZERO; bit A set to binary ZERO; N and L bits set ac-
cording to the normal coding rules.
Frames with operational data on B, D, and E channels; bit
A set to binary ONE.
B1
4
2
B1
3
4
B1 B1 E D A FA N B2 B2
9 10 11 12 13 14 15 16 17
Signals from NT to TE
FA = Auxiliary framing bit or Q-channel bit
N = Bit set to binary value N = FA
A = Activation bit
S = S-channel bit
Q-BIT TRANSMISSION
B1 L
10 11 12 13 14 15
INVERT TO FLAG
FA/N BIT PAIR
Figure 6. Details of NT and TE Frames
(EVERY 5TH FRAME)
D L FA L
Q-BIT OPTION
(continued)
T7234 Single-Chip NT1 (SCNT1) Euro-LITE Transceiver
B2 B2
16 17
48 bits IN 250 s
B2 E D M B1 B1
23 24 25 26 27 28
BIT (OPTIONAL, ONCE
MULTIFRAME SYNC
IN 20 FRAMES)
B2 L
23 24 25 26
INFO 0
INFO 1
INFO 3
M = Multiframe synchronization bit
B1 = Bit within B channel 1
B2 = Bit within B channel 2
D
L
B1 B1
27 28
No signal.
A continuous signal with the following pattern:
positive ZERO, negative ZERO, six ONEs.
Synchronized frames with operational data on B
and D channels.
B1 E D
34 35 36 37 38 39
Signals from TE to NT
B1 L
34 35 36 37
S B2 B2
D
L
B2
38 39
B2
B2 E
45 46 47 48 1
(NT TO TE)
(TE TO NT)
B2 L
45 46 47
D L
D
F
5-2480 (C)
48
L
L
11