Alcatel Carrier Internetworking Solutions 6648 - Manual (Page 343)

Nantucket ASIC
OmniSwitch Troubleshooting Guide September 2005 page -19
Calendar Manager Module
• 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.
Data Port Output Module
• 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.
Nantucket Redundancy
• 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.