RELEASED
PMC-Sierra, Inc.
PM9311/2/3/5 ETT1™ CHIP SET
Data Sheet
PMC-2000164
ISSUE 3
ENHANCED TT1™ SWITCH FABRIC
Table 72. EPP to Scheduler Frame Format
Field
Size (bits)
Meaning
synched
BP VLD
1
1
1
AIB Synched
1 if the QID being read off the BP FIFO should be backpressured
1 if the unbackpressure information is valid
UBP VLD
QID (cast, priority, input port [if unicast, input port ignored if multicast]) for which
backpressure is deasserted.
UBP
8
1
1
5
1
1
1
Input TDM
Req.
Asserted when input has TDM cell to send.
Output
TDM Req.
Asserted when output is ready to receive TDM cell
Input port from which the output is ready to receive TDM cell (valid only if Output TDM
asserted)
TDM Port
Suggested
TDM Sync
1 if this port is currently sending a suggested TDM Sync.
TDM Table
Select
TDM Frame to use next time the Sync is set (only used if this port happens to be
chosen as Master by the Scheduler)
Request
VLD
1 if the best-effort request to follow is valid.
M/U and
control
msg.
If Request VLD is set then this bit indicates if the request is multicast (set to 1) or
unicast (set to 0). If Request VLD is not set then this bit indicates if this frame is a
control message to the Scheduler (set to 1) or just a frame with no request (set to 0).
1
Priority
Fanout
CRC
2
32
8
Priority of request
Multicast fanout if request is multicast, top 5 bits used for output port and bottom 27
bits reserved if the request is unicast.
CRC computed over previous 58 bits
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
321
PMC [ PMC-SIERRA, INC ]
