Alcatel Carrier Internetworking Solutions 8800 User Manual

Nantucket ASIC

OmniSwitch Troubleshooting Guide

page -19

• Generates dequeue requests to the Queue Manager module with priorities of uP packets highest, multi-

cast packets second highest and unicast packets lowest.

• Request dequeues from 512 unicast queues by sending a QID.

• Request dequeues from uP queue by sending FIFO ID.

• Calendar for a Coronado with 24 10/100 ports would be: 0,1,2,3,4,5,6,7,8,9,...,23.

• Calendar for a Coronado with 12 10/100 ports and 1 Gigabit port would be:0,1,0,2,...9,0,10,11,12.

• Memory Manager Module 

• Interfaces between the six SRAMs (32x11264 words) and the data ports.

• Assigns packet chunks to free buffers.

• Queues buffer pointers in per-port queues.

• Returns free buffers to the free buffer list.

• Combines data and control streams into nibble wide output.

• Transmit to the XyPhy Output module (B09) at 125MHz.

• XyPhy Output Module 

• Serializes nibble wide input from the Data Port Output module (B08).

• Transmits serial output at 500MHz.

• The Redundant/Secondary Fabric Board Nantucket ASICs initialize at startup and initialize prior to 

any Primary Fabric Board failures.

• The Nantucket software monitors and detect Primary Fabric failures which includes Fbus link failure, 

no frames received, no backpressure/paychecks received, no calendar pointers are updated, etc.

• When a failure condition is detected that requires switchover to the Secondary Fabric, the Nantucket 

software writes to a register to cause the primary/secondary signal to the Coronado to transition to’0’.

• This will simulate to the Coronado the Primary Fabric being removed.

• The Coronados detect the primary/secondary deasserted signal and perform the failover procedure.

• The method allows all Coronados to switchover at that same time.