cx28250 Mindspeed Technologies, cx28250 Datasheet - Page 46

• Manufacturer Part Number: cx28250
• Description: Cx28250 Atm Physical Interface Phy Devices
• Manufacturer: Mindspeed Technologies

2.0 Functional Description
2.3 SONET/SDH Framer and Overhead Processor
Figure 2-7. STS-3c/STM-1 Basic Frame
2-10
ROW
COLUMN
Section
Line
A1-1 A1-2 A1-3
H1-1 H1-2 H1-3
B2-1 B2-2 B2-3
D10
B1
D1
D4
D7
S1
0
0
0
0
0
0
2.3 SONET/SDH Framer and Overhead Processor
Mindspeed’s CX28250 SONET/SDH framer has an extensive SONET overhead
processing section with external access for D1-D3 and D4-D12 Data Link
message processing. The framer provides data transmission at a standard bit rate,
frequency justification, pointer processing, and SONET frame delineation. The
SONET Overhead processor provides frame synchronization, byte scrambling
and descrambling, and byte multiplexing and demultiplexing.
nine-row rectangle of bytes (octets) shown in
block starts with the first row, working from left to right, then moves to the
second row, left to right, and so on down to the byte in the bottom right corner.
Thus, the transport overhead octets are actually transmitted in nine groups of nine
octets, equally spaced throughout the frame. Since there are 270 x 9 bytes, the
data rate is 270 x 9 x 8 (bits/bytes) x 8,000 fps. (the frame period is 125
micro-seconds) = 155.52 Mbps.
0
0
0
0
0
0
The frame structure for STS-3c/STM-1 can be envisioned as a 270-column by
H2-1
A2-1
D11
D2
K1
D5
D8
Z2
0
Transport
Mindspeed Technologies
H2-2 H2-3
A2-2 A2-3
0
0
0
0
0
0
0
M1
0
0
0
0
0
0
H3-1 H3-2 H3-3
D12
D3
K2
D6
D9
J0
0
0
Z0 1
0
0
0
0
0
0
0
Z0 2
0
0
0
0
0
0
0
™
ATM Physical Interface (PHY) Devices
Figure
Path
G1
B3
C2
J1
0
0
0
0
0
2-7. The transmission of the
PAYLOAD
28250-DSH-002-C
SPE
CX28250
500035_010