Intel IXP400 manual Component Check by Other APIs, Software Configuration

Intel® IXP400 Software

Access-Layer Components: Feature Control (IxFeatureCtrl) API

Table 37. Feature Control Register Values (Sheet 2 of 2)

Bits	Description
5 †	HDLC Coprocessor
4 †	DES Coprocessor
3 †	AES Coprocessor
2 †	Hashing Coprocessor
1 †	USB Coprocessor
0 †	RComp Circuitry

†For bit 0 through 15, 18, 20-21 the following values apply:

•0x0 — The hardware component exists and is not software disabled.

•0x1 — The hardware component does not exist, or has been software disabled.

12.4Component Check by Other APIs

The ixFeatureCtrlComponentCheck( ) function checks for the availability of the specified hardware component. The other Access-Layer components in software release 2.0 use this function during their initialization routines to determine whether the required hardware features are available.

Also, the IxNpeDl API uses the function to prevent the erroneous download of NPE microcode to disabled or unavailable NPEs.

12.5Software Configuration

The provided software configuration structure and supporting functions can be modified at run- time. The software configuration structure is an array that stores the enable/disable state of particular global options. Other software components can be designed to read or write the software configuration array to enable or disable certain software features prior to initialization.

In software release 2.0, there are two entries in the software configuration array;

IX_FEATURECTRL_ETH_LEARNING and IX_FEATURECTRL_ORIGB0_DISPATCHER.

IX_FEATURECTRL_ETH_LEARNING

IxEthDb performs an ixFeatureCtrlSwConfigurationCheck( ) to determine the value of

IX_FEATURECTRL_ETH_LEARNING. IxEthDb uses this value to decide whether or not to activate the NPE-based EthDB learning, and to spawn an Intel XScale core thread to monitor it. Any component or codelet can modify the value prior to IxEthDb initialization using ixFeatureCtrlSwConfigurationWrite(IX_FEATURECTRL_ETH_LEARNING, [TRUE or FALSE]). Once IxEthDB has been initialized, the software configuration cannot be changed.

IX_FEATURECTRL_ORIGB0_DISPATCHER

IxQMgr performs a ixFeatureCtrlSwConfigurationCheck (IX_FEATURECTRL_ORIGB0_DISPA TCHER) to determine if the livelock prevention feature is required. Prior to start of the dispatcher, application users employ ixQMgrDispatcherLoopGet( ) to get the correct queue dispatcher. This feature is configured as TRUE by default, meaning that B-0 versions of the IXP42X product line

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