
STANDARD PRODUCT
PM8315 TEMUX
DATASHEET
PMC-1981125
ISSUE 7
HIGH DENSITY T1/E1 FRAMER  WITH
INTEGRATED VT/TU MAPPER AND M13 MUX
PROPRIETARY AND CONFIDENTIAL
226
Table 32
- DS3 Multi-frame Stuffing Format
V5
4*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
V5
4*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
V5
4*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
V5
4*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
V5
4*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
V5
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
5*R
8*B
DS3 asynchronous timing is compensated via the H3 octet. DS3 link rate
adjustments are optionally passed across the SBI via the Linkrate octet.
Transparent VT1.5/TU11 Mapping
VT1.5 and TU11 virtual tributaries, TVT1.5s, are transported across the SBI bus
in a similar manner to the T1 tributary mapping. Table 33 shows the transparent
structure where “I” is used to indicate information bytes. There are two options
when carrying virtual tributaries on the SBI bus, the primary difference being how
the floating V5 payload is located.
The first option is locked TVT mode which carries the entire VT1.5/TU11 virtual
tributary indicated by the shaded region in Table 33. Locked is used to indicate
that the location of the V1,V2 pointer is locked. The virtual tributary must have a
valid V1,V2 pointer to locate the V5 payload. In this mode the V5 indicator and
payload signals, SDV5, SAV5, SDPL and SAPL, may be generated but must be
ignored by the receiving device. In locked mode timing is always sourced by the
transmitting side, therefore justification requests are not used and the
SAJUST_REQ signal is ignored. Other than the V1 and V2 octets which must
carry valid pointers, all octets can carry data in any format. The location of the
V1,V2,V3 and V4 octets is fixed to the locations shown in Table 33.
The second option is floating TVT mode which carries the payload comprising
the V5 and I octets within the shaded region of Table 33. In this mode the V1,V2
pointers are still in a fixed location and may be valid but are ignored by the
receiving device. The V5 indicator and payload signals, SDV5, SAV5, SDPL and
SAPL, must be valid and are used to locate the floating payload.  (i.e.
SDV5/SAV5 are high during the V5 octet, and SDPL/SAPL are high during all
shaded bytes except the V1/V2/V4 octets and the V3 octet or the octet after V3
depending on pointer movements.)  The justification request signal can be used
to control the timing on the add bus. The location of the V1,V2,V3 and V4 octets
is fixed to the locations shown in Table 33.