herunterladen
2001 Microchip Technology Inc. DS00756A-page 1
M
AN756
INTRODUCTION
The MCP2120 is a cost effective and easy to use
device for sending and receiving IR serial data. The
MCP2120 encodes an asynchronous serial data
stream, converting each data bit to the corresponding
Infrared (IR) formatted pulse. IR pulses that are
received are decoded into the corresponding UART
formatted serial data. The MCP2120 may be used to
add IR capability to any embedded application where
serial data is present. The encoding/decoding function
in the MCP2120 is performed as specified in the phys-
ical layer component of the IrDA
®
standard. This part of
the standard is referred to as “IrPHY”. A detailed dis-
cussion of this standard is beyond the scope of this
Application Note, but a discussion regarding the encod-
ing and decoding is in order. More detailed information
is available from the IrDA website (www.IrDA.org).
The vendor list later in this document also has web-
links to more information. Figure 1 shows typical imple-
mentation of the MCP2120 in an embedded system.
FIGURE 1: SYSTEM BLOCK DIAGRAM
Author: Steve Schlanger
Aegis Technologies LLC.
Encode
Decode
TX
TXIR
RX
RXIR
EN
MCP2120
MICRO-
TX
RX
IRMS6118
UART
TXD
RXD
Baud Rate
BAUD2
Generator
BAUD1
BAUD0
MODE
I/O
CONTROLLER
HSDL-1001
or
Power
Logic
Down
Using The MCP2120 For Infrared Communications
IrDA is a registered trademark of the Infrared Data Association.
