start-last-slot-timer Start the last slot timer. This timer is used to time the transmission of the final XID command frame. A timer may not be necessary. The IrLAP layer just needs to know when the XID frame has been sent so it can then send a SNRM.

log := log { <sa,info> } Add the device address found in an XID response to the device discovery log.

Fast-Connect-Confirm Inform the service user that an IrLAP connection has been created. The IrLAP layer is playing the role of Primary.

send s:rr:cmd:P Send an RR frame. This is the first frame sent by the Primary station when an IrLAP connection is first established.

Send SNRM (sa) Send a SNRM command frame to the device address (sa) returned in an XID response frame.

Fast-Connect-Indication Inform the service user that an IrLAP connection has been created. The IrLAP layer is playing the role of Secondary.

Perform non-IrLAP protocol initialization A non-IrLAP response had been received to a non-IrLAP message so initialize the non-IrLAP protocol and begin executing the non-IrLAP protocol state machine.

Empty Nothing to do.

stop-query-timer Stop the query timer.

Discovery-Indication(remote) The service user is informed that a device (device address from the final XID frame) has been found. This indication is not required for the Fast Connect procedure but could be informative to the service user.

Disconnect-Indication The service user is informed that an attempted IrLAP connection has failed. This indication is not required for the Fast Connect procedure but could be informative to the service user.

stop-P-timer Stop the Poll bit timer.

stop-F-timer Stop the Final bit timer.

5 Auto-detect of 9600 bps and 115.2 kbps

Below is a set of rules and observations that are used in the creation of guideline for automatically detecting (auto-detect) IrDA frames transmitted at 9600 bps and 115.2kbps in NDM.

1.Any byte transmitted at 9600 bps appears as one or more bytes of 0xFF by a receiver at 115.2 kbps. Specifically, 0xFF appears as one 0xFF and 0xC0 appears as seven consecutive 0xFF. (Note: This is not specified in IrPHY but a characteristic of the SIR decoder reference design from Hewlett Packard, 1993. Some SIR decoders do not produce 0xFF if the SIR receiver signal is longer than 1.7 usec. There are three solutions if such a SIR decoder is used. (a) use a SIR receiver that will trim its signal to 1.6 usec, (b) adding a resister, a capacitor, and a diode to trim the SIR receiver signal to 1.6 usec, and (c) adjust the auto detect scheme below to match the characteristic of the SIR decoder used.)

2.Current IrLAP Version 1.1 specifies that in NDM, a) 9600 bps is used, and b) ten extra BOFs (XBOF) of 0xFF or 0xC0 must be transmitted before the real BOF. Thus a receiver at 115.2 kbps will see ten 0xFF or seventy 0xFF before the real BOF at 9.6 kb/s arrives.

3.Devices transmitting at 115.2 kbps in NDM must not transmit any XBOFs (0 XBOFs) but must begin transmission with a single BOF (0xC0).

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The guidelines for auto-detect are as follows:

1.Listen at 115.2 kbps. If a 0xC0 is received, it is the BOF of a 0-XBOF 115.2 kbps frame and the listening device should continue to receive the rest of this frame at 115.2 kbps.

2.If any other byte pattern is received at 115.2 kbps , it should be ignored and go back to 1 above. But there are two exceptions. a) If the specified listening period expires, abort listening, b) If 7 consecutive 0xFF are received and ignored, go to 3 below.

3.Listen at 9600 bps. If 0xFF or 0xC0 is received, it is potentially the remaining XBOF of a 10XBOF 9600 bps frame and the listening device should continue to receive the rest of this frame at 9600 bps.

4.If any byte other than 0xFF or 0xC0 is received before the real BOF at 9600 kbps, go back to 1 above.

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