TMXF28155 Supermapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
Data Sheet
June 2002
446
Agere Systems Inc.
19 VT/TU Mapper Functional Description
(continued)
Table 568. Rx Signaling Behavior Per Channel
* If the P1 bits and P0 bits are not used for phase indication and the F bit is not passed transparently, the F bit is overwritten with the appropri-
ate SF or ESF framing pattern based on a random starting position. Robbed-bit signaling will not be accessible under such a condition.
When operating in the ESF mode, the Ft bits will be overwritten with the ESF frame and the C bits and M bits passed transparently.
19.13 Receive Lower-Order Path Overhead (RX_LOPOH)
The RX_LOPOH logic block (in
Figure 40 on page 435
) will perform all necessary functions to store and transmit
the overhead associated with each VT/TU, specifically, V5, J2, Z6/N2, Z7/K4, and the O bits. The following fea-
tures will be implemented:
I
V5, J2, Z6/N2, Z7/K4, and the 0 bits, on a per-VT basis, are stored for one complete superframe and transmitted
during the next superframe. REI and RDI values received from the SPEMPR and TMUX are stored on a per-
frame basis and transmitted during the next frame. REI and RDI values are latched during the A1 time of the
received SONET frame.
I
When operating in UPSR mode (bit VT_UPSR = 1 (
Table 186 on page 161
)), REI, RDI, and ERDI values in the
V5 and Z7 bytes will be modified based on the receive status. See
Table 573 on page 451
for automatic genera-
tion requirements.
I
The REI and RDI received from the SPEMPR and TMUX blocks is the first data type transmitted in each frame
as a burst of 34 bits on the rising edge of the SPE mapper Rx clock (6.48 MHz). All other data types are transmit-
ted as a burst of 224 bits on the rising edge of the SPE mapper Rx clock.
Note:
The number of valid bits transmitted is dependent upon the VT/TU group types, i.e., full VT2 equals 168 bits.
I
The first frame of the four frame multiframe contains data types 001, 010, 011, and 100, respectively. The second
frame of the multiframe contains data types 001, 101, and 110, respectively. The remaining frames contain only
data type 001. Data type headers will be defined as shown in
Table 569 on page 447
.
All data types must be transmitted within 500 μs.
VT_SYNC_PBIT
[1—28]
VT_WR_FBIT
[1—28]
VT_SF_ESF
[1—28]
VT_LOPS
[1—28]
See Table 190 on
page 163
.
X
X
X
0
0
1
Action
See Table 217 on page 172.
—
0
0
0
1
1
1
0
1
1
1
1
X
X
0*
1
0
1
X
Pass F-bit transparently.
Overwrite outgoing F bit with ESF pattern.
Overwrite outgoing F bit with SF pattern.
Overwrite outgoing F bit with ESF pattern.
Overwrite outgoing F bit with SF pattern.
Transmit DS1 AIS downstream.