Intel NETWORK PROCESSOR IXP2800 - Manual (Page 286)

286 Hardware Reference Manual
Intel
®
IXP2800 Network Processor
Media and Switch Fabric Interface
Table 112 lists the steps to initiate the training. CSIX Full Duplex and CSIX Simplex cases follow
similar, but slightly different sequences.
The last case is when the Switch Fabric indicates it needs Flow Control training. Table 113 lists
that sequence.
Table 112. IXP2800 Network Processor Requires Flow Control Training
Step
CSIX
(IXP2800 Network Processor is Ingress Device)
Full Duplex Simplex
1
Force TXCFC pin asserted (Write a 0 to
Train_Flow_Control [RXCFC_En]). Force Data pins to continuos Dead Cycles
(Write a 1 to Train_Data[Force_CDead]).
2
Egress IXP2800 Network Processor Flow Control port
detects RXCFC sustained assertion and sets
Train_Flow_Control [Detect_TXCFC_Sustained].
Switch Fabric detects Dead Cycles on
Data.
3
Ingress IXP2800 Network Processor transmits
Training Sequence on Flow Control pins (if
Train_Flow_Control [Train_Enable_CFC] is set).
Switch Fabric transmits Training
Sequence on Flow Control pins.
4
When MSF_Interrupt_Status[Received_Training_FC] interrupt indicates training happened and
all of the applicable RX_PHASEMON registers indicate no training errors, write CSR bits set in
Step 1 to inactive value.
Write a 1 to Train_Flow_Control [RXCFC_En]. Write a 1 to Train_Data[Force_CDead].
Table 113. Switch Fabric Requires Flow Control Training
Step
Simplex
(IXP2800 Network Processor is Egress Device)
1 Switch Fabric sends continuous Dead Cycles on Data.
2 Egress IXP2800 Network Processor detects Dead Cycles and sets Train_Data [Detect_CDead].
3
Egress IXP2800 Network Processor transmits Training Sequence on Flow Control pins (if
Train_Flow_Control [Train_Enable_CDead] is set).
4 Switch Fabric, upon getting trained stops continuous Dead Cycles on Data.