Intel IXP400 manual Configuration of Traffic Control Mechanism

Intel® IXP400 Software

Access-Layer Components: ATM Manager (IxAtmm) API

information to the IxAtmDAcc component, as required to drive the transmit function. As a result, all data buffers in the system — once configured — will pass directly through IxAtmdAcc to the appropriate clients. No data traffic will pass through the IxAtmm component at any stage.

Figure 23. Configuration of Traffic Control Mechanism

	Initialization				Data
	Client			Clients
	Port			TxDone	RxHi	RxLo
	Initialization
IxAtmSch	SchTable	Tx Perform
	IxAtmm			IxAtmdAcc			RxLo	Timer
		RxLo Config
		RxHi Config
		TxDone Config		TxDone	RxHi	RxLo
	Tx	TxConfig	Tx
	Intel© IXP4XX/IXC1100 Hardware
	Configuration
	Callback Source
	Data Path
								B2293-01

Only transmit traffic — which has already been queued by the client with IxAtmdAcc when the request for more traffic is made — will be scheduled and sent to the hardware. (That is, no callback to the data client will be made in the context of the transmit processing.) IxAtmdAcc makes IxAtmSch aware of the existence of this pending traffic when it is queued by the client through the use of a previously registered callback interface.

The supply of empty buffers to the hardware — for use in the receive direction — is the responsibility of the individual client on each active VC. As a result, the target callback for this event on each VC is outside of the visibility of the IxAtmm component, being part of the client logic. It is the responsibility of each client, therefore, to ensure that the supply mechanism of free buffers for receive processing is configured correctly before traffic may begin passing on the system.

April 2005	IXP400 Software Version 2.0	Programmer’s Guide
76	Document Number: 252539, Revision: 007