Intel® IXP400 Software

Access-Layer Components: Ethernet Access (IxEthAcc) API

Figure 50. Ethernet Transmit Frame Data Buffer Flow

1.Initializations , Port Enables, Callback Registration...

2.Frame Submit (Port 0) Frame Submit (Port 1) Frame Submit (Port 2)

FIFO_PRIORITY FIFO_NO_PRIORITY

3a. Route Tx buffers to

 

 

3b. Load Tx

8 priority queues

 

 

Queues

 

 

 

 

 

 

 

 

directly

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sw queue for deferred submission

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4.Load Tx Queues when low threshold reached

Codelet or client application

8.TxDoneCallback (Port 0) TxDoneCallback (Port 1) TxDoneCallback (Port 2)

IxEthAcc

7.Demux free buffer to port specific callback

IxQMgr

TxEnet0

TxEnet1

TxEnet2

6. ixp_buf moved to TxDone

TxEnetDone

 

queue

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5.Move to NPE queue,

then physical transmission

NPE B NPE C NPE A

B2364-04

There are two scheduling disciplines selectable via the IxEthAccTxSchedulerDiscipline (). The frame submit behavior will be different for each case. Available scheduling disciplines are No Priority and Priority.

April 2005

IXP400 Software Version 2.0

Programmer’s Guide

136

Document Number: 252539, Revision: 007

 

Page 136
Image 136
Intel IXP400 manual Ethernet Transmit Frame Data Buffer Flow, TxEnetDone