Released
PMC-Sierra, Inc.
PM9311/2/3/5 ETT1™ CHIP SET
Data Sheet
PMC-2000164
ISSUE 3
ENHANCED TT1™ SWITCH FABRIC
1.6.2 Use of Label and Type Fields
This section provides detail about the generic 14-bit labels and 4-bit types defined in Table 7, Table 8,
Table 9, and Table 10. In all cases, in multi-bit fields, the MSB is transmitted first. For each segment, the
“Type Field” and “Label Field” are encoded as follows:
Table 7. Encoding of 4-bit Type Fields
Type[3:0]
Segment Type
Use
0000
Control Packet
Provides for inband control information between the
linecard and the switch core.
0001,...,0110
0111
Reserved for future use
TDM
Currently not defined for use.
TDM service provides preallocated bandwidth at a
regular time interval.
1000,...,1011
1100,...,1111
Unicast Best-Effort (Priority 0,1,2,3)
Multicast Best-Effort (Priority 0,1,2,3)
Prioritized unicast service where priority 0 is the
highest priority.
Prioritized multicast service where priority 0 is the
highest priority.
Table 8. Usage of the Ingress Request Label_1
Segment Type
Type_1
Encoding of Request Label_1[13:0]
a
Control Packet
TDM
0000
Rsvd (13), CP-category (1). CP-category = 0 for LCS Control Packets;
CP-category = 1 for CPU Control Packets.
b
c
0111
10xx
MUX (2) , Expansion (2), TDM Tag (10)
b
d
e
Unicast Best-Effort
(Priority 0,1,2,3)
MUX (2) , Expansion (5), Destination Port (5), Destination subport (2)
b
Multicast Best-Effort
(Priority 0,1,2,3)
11xx
MUX (2) , Multicast Tag (12)
a. Reserved. All bits labeled Rsvd must be set to zero.
b. The MUX[1:0] field is placed at the beginning of the Request Label_1 field in all segments (i.e. both data traffic and con-
trol packets). If this field is not used for a MUX function, it can be used as additional bits for expansion. If not used, it
must be set to zero.
c. TDM Expansion field used in products if the number of TDM slots is increased. If this field is used, the “TDM Tag” field
will increase contiguously. If not used, must be set to zero.
d. Unicast Expansion field used in products if the number of ports is increased. If this field is used, the “Destination Port”
field will increase contiguously. If not used, must be set to zero.
e. If the port has no subports (i.e. if it is connected to a single linecard without multiplexing), this field must be set to zero.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
67
PMC [ PMC-SIERRA, INC ]
