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The following Physical Layer Specification is dependent on the opti-
cal transceiver logic used in the application. The specification states:
• Communication range, which sets the end user expectation for
discovery, recognition, and performance.
• Continuous operation from contact to at least 1 m (typically 2 m
can be reached).

• A low power specification reduces the objective for operation
from contact to at least 20 cm (low power and low power) or 30
cm (low power and standard power).

IrLAP. The MCP2150 supports the IrLAP. The IrLAP provides:

• Management of communication processes on the link between
devices.

• A device-to-device connection for the reliable, ordered transfer
of data.

• Device discover procedures.

• Hidden node handling.
Figure 5.26 identifies the key parts and hierarchy of the IrDA proto-
cols. The bottom layer is the Physical layer, IrPHY. This is the part that
converts the serial data to and from pulses of IR light. IR transceivers
can’t transmit and receive at the same time. The receiver has to wait
for the transmitter to finish sending. This is sometimes referred to as
a “half-duplex” connection. The IR IrLAP provides the structure for

Figure 5.26
Key IrDA protocols.

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