Intel IXP400 manual IxNpeMh

Intel® IXP400 Software

Access-Layer Components: NPE Message Handler (IxNpeMh) API

7.Because this is a solicited message, the first ID-matching callback is removed from the solicited callback list and invoked to pass the message back to the client.

If no ID-matching callback is found, the message is discarded and an error reported.

Figure 72. Message with Response from Intel XScale® Core Software Client to an NPE

	Client
Customer / Demo Code	1. Send Message
	7. Response Callback
0x00 callback	2. Save Callback		callback n+k
0x01 callback			...
...			callback n+1
0xff callback	IxNpeMh		callback n
		6. Get Callback
3. Send
Message
Access Driver	5. Receive
	Message
NPEs	4. Message
	Interrupt
NPE A	NPE B		NPE C
			B2396-01

15.6Receiving Unsolicited Messages from an NPE to Client Software

The scenario of receiving unsolicited messages from an NPE to client software (as shown in Figure 73) is:

1.At initialization, the client registers an unsolicited callback for a particular NPE and a message ID.

2.After some time, the NPEs “outFIFO not empty” interrupt invokes the IxNpeMh component’s ISR.

3.Within the ISR, the IxNpeMh component receives a message from the specific NPE.

4.The IxNpeMh component determines if this message ID has an unsolicited callback registered for it.

If the message ID does not have a registered unsolicited callback, the message is solicited. (See “Sending an NPE Message with Response” on page 228.)

Programmer’s Guide	IXP400 Software Version 2.0	April 2005
	Document Number: 252539, Revision: 007	229