tmxf28155 ETC-unknow, tmxf28155 Datasheet - Page 432

• Manufacturer Part Number: tmxf28155
• Description: Tmxf28155 Super Mapper 155/51 Mbits/s Sonet/sdh X28/x21 Ds1/e1
• Manufacturer: ETC-unknow

155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
19 VT/TU Mapper Functional Description
19.6 VT/TU Mapper Receive Path Description
This section describes all necessary functions of the receive logic (see
19.7 VT Demultiplexer (VTDEMUX)
The VTDEMUX logic block (in
tributary (VT) is active on the data bus.
This block monitors the H4 byte and frames on the H4 multiframe indication. In frame (VT_H4LOMF = 0
(Table
consists of four consecutive frames containing a (00, 01, 10, 11) pattern in the two LSBs of the H4 byte. Once
framed, H4 loss of multiframe (VT_H4LOMF = 1) will be declared following the number of consecutive mismatches
in the H4 multiframe indication programmed into bits VT_H4_NTIME[3:0]
ment will generate AIS downstream. A change in H4 multiframe alignment is indicated by bit VT_H4LOMF_D
(Table
Bits VT_RX_GRP_TYPE[6:0]
VT1.5/TU-11 or a VT2/TU-12.
See
19.8 VT Pointer Interpreter (VTPI)
The VTPI logic block (in
pretation. The following features are implemented:
The pointer interpreter consists of the following states:
432
Virtual tributary demultiplexor (VTDEMUX)
Virtual tributary pointer interpreter (VTPI)
Virtual tributary terminator (VTTERM)
Output selector (OUTSEL)
J2 16-byte sequence monitor (J2MON)
Receive VT/TU signaling (RX_VTSIG)
Receive low-order path overhead (RX_LOPOH)
Loss of pointer (LOP-V)
VT-AIS (AIS-V) (all ones in V1 and V2)
NDF enabled (NDF) (1001, 0001, 1101, 1011, 1000)
Normal (NORM) (disabled NDF, normal pointer)
Increment (INC) (inverted I bits)
Decrement (DEC) (inverted D bits)
Table 551
176)) will be declared following two consecutive, nonerrored multiframe indications. A multiframe indication
168) and will generate an interrupt unless the mask is set (VT_H4LOMF_M = 1
through
Table 554
Figure 39 on page429
(Table
Figure 39 on page429
on
180) are programmed to determine whether the incoming tributary is a
page 430
) will perform all necessary functions to support VT/TU pointer inter-
through
) will perform all necessary functions to decode which virtual
page 431
(continued)
for VT/TU mapping formats.
Figure
(Table
39, right to left):
182). Loss of H4 multiframe align-
(Table
180)).
Agere Systems Inc.
May 2001