1.0 DEVICE OVERVIEW
The MCP2140A is a cost-effective, low pin count (18-
pin), easy-to-use device for implementing IrDA
standard wireless connectivity. The MCP2140A
provides support for the IrDA standard protocol “stack”,
bit encoding/decoding and low cost, discrete IR
receiver circuitry. The MCP2140A is footprint
compatible with the MCP2140. For migration
assistance, please refer to Section 2.14 “Migrating
from the MCP2140 to the MCP2140A”.
The serial and IR interface baud rates are fixed at
9600 baud. The serial interface and IR interface baud
rates are dependent on the device frequency, but IrDA
standard operation requires a device frequency of
The MCP2140A will specify the IR baud rate to the
Primary Device during the Discover phase.
The MCP2140A can operate in Data Communication
Equipment (DCE) and Data Terminal Equipment (DTE)
applications, and resides between a UART and an
infrared optical transceiver.
The MCP2140A encodes an asynchronous serial data
stream, converting each data bit to the corresponding
infrared (IR) formatted pulse. IR pulses received are
decoded and then handled by the protocol handler
state machine. The protocol handler sends the
appropriate data bytes to the Host Controller in UART-
formatted serial data.
The MCP2140A supports “point-to-point” applications,
that is, one Primary device and one Secondary device.
The MCP2140A operates as a Secondary device and
does not support “multi-point” applications.
Sending data using IR light requires some hardware
and the use of specialized communication protocols.
These protocol and hardware requirements are
described, in detail, by the IrDA standard specifica-
tions. The encoding/decoding functionality of the
MCP2140A is designed to be compatible with the
physical layer component of the IrDA standard. This
part of the standard is often referred to as “IrPHY”.
Some of the devices that the MCP2140A is compatible
• PCs with IR ports
• 16-bit PIC Microcontroller IrDA Standard Stack
The complete IrDA standard specification is available
for download from the IrDA web site at www.IrDA.org.
The MCP2140A Infrared Communications Controller,
supporting the IrDA standard, provides embedded
system designers the easiest way to implement IrDA
standard wireless connectivity. Figure 1-1 shows a
typical application block diagram, while Table 1-1
shows the pin definitions.
TABLE 1-1: OVERVIEW OF FEATURES
Baud Rate Selection
Low Power Mode
Resets (and Delays)
Yes - Automatic
(PWRT and OST)
18-pin DIP, SOIC,
Infrared communication is a wireless, two-way data
connection using infrared light generated by low-cost
transceiver signaling technology. This provides reliable
communication between two devices.
Infrared technology offers:
• Universal standard for connecting portable
• Easy, effortless implementation
• Economical alternative to other connectivity
• Reliable, high-speed connections
• Safe to use in any environment (can even be
used during air travel)
• No emissions testing needed (FCC, Part 15)
• Eliminates the hassle of cables
• Allows PCs and other electronic devices (such as
PDAs, cell phones, etc.) to communicate with
• Enhances mobility by allowing users to easily
The MCP2140A allows the easy addition of IrDA
standard wireless connectivity to any embedded
application that uses serial data. Figure 1-1 shows
typical implementation of the MCP2140A in an
The IrDA protocol for printer support is not included in
the IrCOMM 9-wire “cooked” service class.
© 2007 Microchip Technology Inc.