M
Features
• Implements the IrDA
®
standard, including:
- IrLAP
- IrLMP
- IAS
- TinyTP
- IrCOMM (9-wire “cooked” service class)
• Provides IrDA standard physical signal layer
support including:
- Bidirectional communication
- CRC implementation
- Fixed Data communication rate of 9600 baud
• Includes UART-to-IrDA standard encoder/
decoder functionality:
- Easily interfaces with industry standard
UARTs and infrared transceivers
• UART interface for connecting to Data
Communications Equipment (DCE) or Data
Terminal Equipment (DTE) systems
• Transmit/Receive formats (bit width) supported:
- 1.63 µs
• Hardware UART Support:
- 9.6 kbaud baud rate
- 29 Byte Data Buffer Size
• Infrared Supported:
- 9.6 kbaud baud rate
- 64 Byte Data Packet Size
• Operates as Secondary Device
• Automatic Low Power mode
- < 60 µA when no IR activity present
(PHACT = L)
MCP2140
Package Types
PDIP, SOIC
RXPDREF
TXIR
PHACT
RESET
V
SS
NC
TX
RX
RI
1
2
3
4
5
6
7
8
9
18
17
16
15
14
13
12
11
10
RXPD
CD
OSC1/CLKI
OSC2
V
DD
RTS
CTS
DTR
DSR
IrDA
®
Standard Protocol Stack Controller
With Fixed 9600 Baud Communication Rate
MCP2140
SSOP
RXPDREF
TXIR
PHACT
RESET
V
SS
V
SS
NC
TX
RX
RI
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
RXPD
CD
OSC1/CLKI
OSC2
V
DD
V
DD
RTS
CTS
DTR
DSR
MCP2140
Block Diagram
MCP2140
TX
Encode and
Protocol Handler
Logic
PHACT
Baud
Rate
Generator
Protocol
Handler
and Decode
+
-
RXPD
RXPDREF
OSC1
OSC2
TXIR
CMOS Technology
•
•
•
•
•
Low power, high-speed CMOS technology
Fully static design
Low voltage operation
Industrial temperature range
Low power consumption
- < 1 mA @ 3.0V, 7.3728 MHz (typical)
RX
RTS
CTS
DSR
DTR
CD
RI
UART
Control
2003 Microchip Technology Inc.
Preliminary
DS21790A-page 1
MCP2140
1.0
DEVICE OVERVIEW
1.1
Applications
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.
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
MCP2140
UART, IR
Fixed
Yes
RESET, POR
(PWRT and OST)
18-pin DIP, SOIC,
20-pin SSOP
Features
Serial Communications
Baud Rate Selection
Low Power Mode
Resets (and Delays)
Packages
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
MCP2140
TABLE 1-2:
Pin Name
RXPDREF
TXIR
PHACT
MCP2140 PIN DESCRIPTION NORMAL OPERATION (DCE)
Pin Number
PDIP
1
2
3
SOIC
1
2
3
SSOP
1
2
3
Pin
Type
I
O
OC
Buffer
Type
A
—
—
Description
IR Receive Photo Detect Diode reference voltage. This
voltage will typically be in the range of V
DD
/2.
Asynchronous transmit to IrDA transceiver.
Protocol Handler Active. Indicates the state of the MCP2140
Protocol Handler. This output is an open collector, so an
external pull-up resistor may be required.
1
= Protocol Handler is in the Discovery or NRM state
0
= Protocol Handler is in NDM state or the MCP2140 is
in Low Power mode
Resets the Device
Ground reference for logic and I/O pins
No connect
Asynchronous receive; from Host Controller UART
Asynchronous transmit; to Host Controller UART
Ring Indicator. The state of this bit is communicated to the
IrDA Primary Device.
1
= No Ring Indicate Present
0
= Ring Indicate Present
Data Set Ready. Indicates that the MCP2140 has estab-
lished a valid IrDA link with a Primary Device
(1)
. This signal
is locally emulated and not related to the DTR bit of the IrDA
Primary Device.
1
= An IR link has not been established
(No IR Link)
0
= An IR link has been established (IR Link)
Data Terminal Ready. Indicates that the Embedded device
connected to the MCP2140 is ready for IR data. The state of
this bit is communicated to the IrDA Primary Device via the
IrDA DSR bit carried by IrCOMM.
1
= Embedded device not ready
0
= Embedded device ready
Clear to Send. Indicates that the MCP2140 is ready to
receive data from the Host Controller. This signal is locally
emulated and not related to the CTS/RTS bit of the IrDA
Primary Device.
1
= Host Controller should not send data
0
= Host Controller may send data
RESET
V
SS
NC
TX
RX
RI
4
5
6
7
8
9
4
5
6
7
8
9
4
5, 6
7
8
9
10
I
—
I
I
O
I
ST
P
—
TTL
—
TTL
DSR
10
10
11
O
—
DTR
11
11
12
I
TTL
CTS
12
12
13
O
—
Legend:
TTL = TTL compatible input
A = Analog
CMOS = CMOS compatible input
I = Input
ST = Schmitt Trigger input with CMOS levels
P = Power
OC = Open collector output
O = Output
1:
The state of the DTR output pin does not reflect the state of the DTR bit of the IrDA Primary Device.
2003 Microchip Technology Inc.
Preliminary
DS21790A-page 5
PCB Design
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