PM73121ꢀAAL1gator II
Data Sheet
PMC-Sierra, Inc.
PMC-980620
,VVXHꢀꢁ
AAL1 SAR Processor
(DS0s), which are 64 Kbit/s channels, the AAL1gator II is an ideal vehicle for constructing
ATM-based DACS and other circuit emulation devices. Structured data format is suited for these
types of networks and underlying services. The SDF-MF mode is primarily used for applications
that need to pass CAS, which carries the ABCD signaling bits. CAS is still common in many
TDM networks. The SDF-FR mode, which transfers no signaling, is also supported.
In SDF-MF mode, individual queues can be configured to transfer no signaling. This is the equiv-
alent to SDF-FR mode for a given queue.
2.1.1 Structured Cell Formats
Figure 8 shows examples of four structured cell formats. In the partially filled cell examples, the
partially filled level has been set to 42 payload bytes.
GFC/VPI
VPI
VPI
VCI
GFC/VPI
VPI
VPI
VCI
GFC/VPI
VPI
VPI
VCI
GFC/VPI
VPI
VPI
VCI
VCI
VCI
VCI
VCI
VCI
PTI
HEC
CLP
VCI
PTI
HEC
CLP
VCI
PTI
HEC
CLP
VCI
PTI
HEC
CLP
CSI
SN
SNP
CSI
SN
SNP
CSI
SN
SNP
CSI
SN
SNP
Pointer
Payload 1
Payload 2
Pointer
Payload 1
Payload 2
Payload 1
Payload 1
.
.
.
.
.
.
.
.
.
.
.
.
Payload 42
Payload 42
Payload 46
Payload 47
Cell with Pointer
46 Payload Bytes
Cell without Pointer
47 Payload Bytes
Partially Filled Cell with Pointer Partially Filled Cell without Pointer
42 Payload Bytes 42 Payload Bytes
Figure 8. Examples of Structured Cell Formats
ꢀꢄ
PMC [ PMC-SIERRA, INC ]
