MCP2140A Microchip Technology, MCP2140A Datasheet - Page 12

• Manufacturer Part Number: MCP2140A
• Description: IrDA Standard Protocol Stack Controller With Fixed 9600 Baud Communication Rate
• Manufacturer: Microchip Technology

MCP2140A
2.5
The encoder converts the UART format data into the
IrDA Standard format data and the decoder converts
IrDA Standard format data into UART format data.
2.5.1
The data that the MCP2140A UART received (on the
TX pin) that needs to be transmitted (on the TXIR pin)
is modulated. This modulated signal drives the IR
transceiver module.
the modulated signal.
FIGURE 2-6:
DS22050A-page 12
Note:
BITCLK
TX Bit
Value
TXIR
Encoder/Decoder
ENCODER (MODULATION)
The signal on the TXIR pin does not
actually line up in time with the bit value
that was transmitted on the TX pin, as
shown in
shown to represent the value to be
transmitted on the TXIR pin.
Figure 2-6
Start Bit
Figure
16 CLK
ENCODING
0
2-6. The TX bit value is
7 CLK
shows the encoding of
12 Tosc
Data bit 0
1
Data bit 1
0
Each bit time is comprised of 16-bit clocks. If the value
to be transmitted (as determined by the TX pin) is a
logic-low, the TXIR pin will output a low level for 7-bit
clock cycles, a logic high level for 3-bit clock cycles or
a minimum of 1.6 µs (see
remaining 6-bit clock cycles will be low. If the value to
transmit is a logic-high, the TXIR pin will output a low
level for the entire 16-bit clock cycles.
Data bit 2
0
Data bit ...
1
© 2007 Microchip Technology Inc.
Parameter
0
IR121). The