MCP2140_03 Datasheet, PDF (3/58 Pages) Microchip Technology – IrDA® Standard Protocol Stack Controller With Fixed 9600 Baud Communication Rate

1.0 DEVICE OVERVIEW
The MCP2140 is a cost-effective, low pin count (18-pin),
easy-to-use device for implementing IrDA standard
wireless connectivity. The MCP2140 provides support
for the IrDA standard protocol “stack”, bit encoding/
decoding and low cost, discrete IR receiver circuitry.
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
7.3728 MHz.
The MCP2140 will specify to the Primary Device the IR
baud rate during the Discover phase.
The MCP2140 can operate in Data Communication
Equipment (DCE) and Data Terminal Equipment (DTE)
applications, and sits between a UART and an infrared
optical transceiver.
The MCP2140 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 appro-
priate data bytes to the Host Controller in UART-
formatted serial data.
The MCP2140 supports “point-to-point” applications,
that is, one Primary device and one Secondary device.
The MCP2140 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 specifications.
The encoding/decoding functionality of the MCP2140 is
designed to be compatible with the physical layer com-
ponent of the IrDA standard. This part of the standard is
often referred to as “IrPHY”.
The complete IrDA standard specification is available
for download from the IrDA website at www.IrDA.org.
MCP2140
1.1 Applications
The MCP2140 Infrared Communications Controller,
supporting the IrDA standard, provides embedded sys-
tem designers the easiest way to implement IrDA stan-
dard wireless connectivity. Figure 1-1 shows a typical
application block diagram, while Table 1-2 shows the
pin definitions.
TABLE 1-1: OVERVIEW OF FEATURES
Features
MCP2140
Serial Communications UART, IR
Baud Rate Selection
Low Power Mode
Fixed
Yes
Resets (and Delays)
Packages
RESET, POR
(PWRT and OST)
18-pin DIP, SOIC,
20-pin SSOP
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
computing devices
• Easy, effortless implementation
• Economical alternative to other connectivity
solutions
• Reliable, high-speed connections
• Safe to use in any environment (can even be
used during air travel)
• Eliminates the hassle of cables
• Allows PCs and other electronic devices (such as
PDAs, cell phones, etc.) to communicate with
each other
• Enhances mobility by allowing users to easily
connect
The MCP2140 allows the easy addition of IrDA stan-
dard wireless connectivity to any embedded applica-
tion that uses serial data. Figure 1-1 shows typical
implementation of the MCP2140 in an embedded
system.
The IrDA protocol for printer support is not included in
the IrCOMM 9-wire “cooked” service class.
 2003 Microchip Technology Inc.
Preliminary
DS21790A-page 3