CONTROLINK86 SMSC, CONTROLINK86 Datasheet - Page 28

• Manufacturer Part Number: CONTROLINK86
• Description: Development Software Embedded Networking Software
• Manufacturer: SMSC

Specifications of CONTROLINK86

• Tool Function: Compiler
• Tool Type: Compiler
• Processor Series: 80x86
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ControLink86 Realtime Networking Software
The exchange Identification request is an 802.2 function that conveys information regarding the LLC Class 1
and receive window size (number of receive buffers). Future revisions of ControLink will include an enhanced
XID frame that appends an eight character ASCII label and SAP address associated with the label. Any node
receiving an XID frame will automatically respond with an XID response frame that includes the same
information. Since every Class 1 message has a SSAP and DSAP, the XID frame can be used to establish
the existence of a physical node and a particular SAP address in a given node. The idea of the exchanging
IDs is illustrated by the Figure 6.
Example:
3.6.2.3TEST REQUEST
The TEST request invokes an 802.2 function that is intended for use to test the data integrity of a
particular link. This procedure is illustrated in the Figure 7.
The TEST function allows the user to select the length and pattern of the test message (include a data
field in the test message). When the host issues a TEST request the Class 1 driver will send a TEST
command to the node to be tested. The node receiving the TEST will automatically generate a TEST
response message that is sent back to the originating node. If the TEST request contains a custom data,
this data is returned in the reply. This call/response methodology results in an accurate link integrity test
/* check what class services are available at the other stations */
…
event = XID_REQUEST
status = llc1_request (x, y, event, & 1sap[x]);
…
MAC Packet SENDING
MAC Packet RECEIVING
Note: ACK (Acknowledgement) packets are not represented here
(SENDER)
Application
Link Test
Link Test
Indication
Request
Host
Burst
Burst
Alert
Alert
0x01
0x01
SRC
SRC
ID
ID
Logical Link
(SENDER)
Destination
DEST
DEST
Control
Source
ID
ID
SAP x
SAP x
DEST
DEST
FIGURE 7 - LINK TEST PROCEDURE
ID
ID
Count
Count
0x03
0x03
0x00
0x00
MAC Packet
(MAC Layer)
MAC Packet
DSAP
DSAP
MEDIUM
y
x
28
SSAP
SSAP
x
y
0xE3
0xF3
optional data
optional data
pattern
pattern
generated when
Test Indication
(RECEIVER)
llc1_service()
automatically
Logical Link
Response is
Destination
to Class1
Control
is called
Source
SAP y
SAP y
Driver
CRC
CRC
CRC
CRC
(RECEIVER)
Application
Host