
Preliminary Data Sheet, Rev. 1
October 2000
TMXF28155 Super Mapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
431
Lucent Technologies Inc.
28-Channel Framer Block Functional Description
(continued)
Facility Data Link
(continued)
DDS Receive Data Link Stack
n
Extracts data link bit (bit 6) from time slot 24 and stores into stack.
n
Provides interrupt for stack ready.
n
Provides host access to stack using processor clock to provide fast access.
n
Supports loss of frame status.
DDS frames are numbered 1 through 12 with the data link bits located in bit 6 of time slot 24 in every frame. Only
basic frame alignment must be established for the data link bits to be extracted.
The DDS stack is stored in the shared Rx stack as follows.
Table 316. Shared Rx FDL Stack Format for DDS Frames
Starting at every superframe boundary the data link bits are stored in an internal copy of the shared Rx stack. As
the data link bits are accumulated, the data link bits from the first superframe are stored in word 0. The frame
aligner block will give an indication of loss of frame alignment which is used by the data link block to determine if
the data link bits collected are invalid. In this case, they will not be made available to the system.
When the entire stack has been filled (three superframes) the host is notified using the Rx stack ready interrupt.
After the Rx stack ready interrupt bit is set, the host has approximately 4.5 ms to read the stack.
CEPT; CEPT CRC-4 (100 ms); CEPT CRC-4 (400 ms) Multiframe Sa Bits Receive Stack
n
Extracts two multiframes of Sa bits from CEPT links and stores them in internal memory.
n
Supports loss of frame status.
n
Provides host access to the stack using the processor clock.
n
Provides interrupt for stack ready.
CEPT frames are numbered 0 through 15 with the Sa bits located in time slot 0 of the odd numbered frames. The
Sa bits can only be extracted from CEPT links when the proper alignment has been established.
For basic CEPT frames the Sa bits will be extracted given the arbitrary alignment selected by the frame aligner
block when basic frame alignment is established. For CEPT CRC-4 links the Sa bits will be extracted based on the
alignment determined by the frame aligner block when multiframe frame alignment is established.
Optionally, the Sa bits will be extracted from CEPT CRC-4 links only after basic frame alignment is established
(RxCRCSM).
Word
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
1
2
3
4
D1
D1
D1
—
—
D2
D2
D2
—
—
D3
D3
D3
—
—
D4
D4
D4
—
—
D5
D5
D5
—
—
D6
D6
D6
—
—
D7
D7
D7
—
—
D8
D8
D8
—
—
D9
D9
D9
—
—
D10
D10
D10
—
—
D11
D11
D11
—
—
D12
D12
D12
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—