2003 Microchip Technology Inc.
Preliminary
DS21790A-page 1
M
MCP2140
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 s
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 A when no IR activity present
(PHACT = L)
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)
Package Types
Block Diagram
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
1
19
18
16
15
14
13
12
11
17
18
17
15
14
13
12
11
10
16
20
OSC2
OSC1/CLKI
V
SS
V
SS
V
DD
V
DD
RXPD
CD
CTS
RTS
TX
RX
RI
DSR
DTR
TXIR
PHACT
RESET
NC
RXPDREF
V
SS
TX
RX
RI
TXIR
PHACT
RESET
NC
RXPDREF
OSC2
OSC1/CLKI
V
DD
RXPD
CD
CTS
RTS
DSR
DTR
MC
P
2
1
4
0
MC
P2
1
4
0
PDIP, SOIC
SSOP
Encode and
Protocol
TX
TXIR
RX
RXPD
MCP2140
Baud
RTS
Generator
CD
CTS
DSR
DTR
RI
OSC1
OSC2
Protocol Handler
and Decode
RXPDREF
Handler
+
-
PHACT
Logic
Rate
UART
Control
IrDA
Standard Protocol Stack Controller
With Fixed 9600 Baud Communication Rate
2003 Microchip Technology Inc.
Preliminary
DS21790A-page 3
MCP2140
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.
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
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.
Features
MCP2140
Serial Communications
UART, IR
Baud Rate Selection
Fixed
Low Power Mode
Yes
Resets (and Delays)
RESET, POR
(PWRT and OST)
Packages
18-pin DIP, SOIC,
20-pin SSOP
2003 Microchip Technology Inc.
Preliminary
DS21790A-page 5
MCP2140
TABLE 1-2:
MCP2140 PIN DESCRIPTION NORMAL OPERATION (DCE)
Pin Name
Pin Number
Pin
Type
Buffer
Type
PDIP
SOIC SSOP
Description
RXPDREF
1
1
1
I
A
IR Receive Photo Detect Diode reference voltage. This
voltage will typically be in the range of V
DD
/2.
TXIR
2
2
2
O
--
Asynchronous transmit to IrDA transceiver.
PHACT
3
3
3
OC
--
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
RESET
4
4
4
I
ST
Resets the Device
V
SS
5
5
5, 6
--
P
Ground reference for logic and I/O pins
NC
6
6
7
I
--
No connect
TX
7
7
8
I
TTL
Asynchronous receive; from Host Controller UART
RX
8
8
9
O
--
Asynchronous transmit; to Host Controller UART
RI
9
9
10
I
TTL
Ring Indicator. The state of this bit is communicated to the
IrDA Primary Device.
1
= No Ring Indicate Present
0
= Ring Indicate Present
DSR
10
10
11
O
--
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)
DTR
11
11
12
I
TTL
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
CTS
12
12
13
O
--
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
Legend:
TTL = TTL compatible input
ST = Schmitt Trigger input with CMOS levels
A = Analog
P = Power
CMOS = CMOS compatible input
OC = Open collector output
I = Input
O = Output
1: The state of the DTR output pin does not reflect the state of the DTR bit of the IrDA Primary Device.
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