Intel IXP400 manual Transmission Triggers Tx-Low Notification, Transmit-Done Processing

Intel® IXP400 Software

Access-Layer Components: ATM Driver Access (IxAtmdAcc) API

Figure 15. IxAtmdAccScheduleTable Structure and Order Of ATM Cell

							Schedule table
							ixAtmdScheduleTable
							Table size : 5
							Table entry Ptr
							TotalCellSlots : 9:
							ixAtmdScheduleTableEntry
							ConnectionId 12
							NumberOfCells 2
							ConnectionId 6
							NumberOfCells 1
							IX_ATMDACC_IDLE_CELLS
							NumberOfCells 1
							ConnectionId 12
							NumberOfCells 2
							IX_ATMDACC_IDLE_CELLS
							NumberOfCells 1
12	12	6	IDLE	12	12	IDLE	Cells transmitted on the ATM port
							B2285-01

4.5.2Transmission Triggers (Tx-Low Notification)

In Scheduled Mode, the rate and exact point at which the ixAtmdAccTxProcess() interface should be called by the shaping entity is at the client’s discretion and hence beyond the scope of this document.

However, ixAtmdAcc transmit service does provide a Tx-Low Notification service which can be configured to execute a client-supplied notification callback, when the number of cells not yet transmitted by the hardware reaches a certain low level. The service only supports a single client per port and the maximum default cell threshold is eight cells.

4.5.2.1Transmit-Done Processing

When buffers have been sent on a port, they are placed in a single, transmit-complete stream, which is common to all ports. IxAtmdAcc does not autonomously process this stream — the client, instead, deciding when and how many buffers will be processed.

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