ATSAM3U-EK Atmel, ATSAM3U-EK Datasheet - Page 715

• Manufacturer Part Number: ATSAM3U-EK
• Description: KIT EVAL FOR AT91SAM3U CORTEX
• Manufacturer: Atmel
• Type: MCUr

Specifications of ATSAM3U-EK

• Contents: Board
• Processor To Be Evaluated: SAM3U
• Data Bus Width: 32 bit
• Interface Type: RS-232, USB
• Operating Supply Voltage: 3 V
• Silicon Manufacturer: Atmel
• Core Architecture: ARM
• Core Sub-architecture: Cortex - M3
• Silicon Core Number: SAM3U4E
• Silicon Family Name: SAM3U
• Kit Contents: Board CD Docs
• Rohs Compliant: Yes
• For Use With/related Products: AT91SAM3U
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

35.7.5
35.7.5.1
6430D–ATARM–25-Mar-11
6430D–ATARM–25-Mar-11
IrDA Mode
IrDA Modulation
The USART features an IrDA mode supplying half-duplex point-to-point wireless communica-
tion. It embeds the modulator and demodulator which allows a glueless connection to the
infrared transceivers, as shown in
with the IrDA specification version 1.1 and support data transfer speeds ranging from 2.4 Kb/s to
115.2 Kb/s.
The USART IrDA mode is enabled by setting the USART_MODE field in the Mode Register
(US_MR) to the value 0x8. The IrDA Filter Register (US_IF) allows configuring the demodulator
filter. The USART transmitter and receiver operate in a normal asynchronous mode and all
parameters are accessible. Note that the modulator and the demodulator are activated.
Figure 35-32. Connection to IrDA Transceivers
The receiver and the transmitter must be enabled or disabled according to the direction of the
transmission to be managed.
To receive IrDA signals, the following needs to be done:
For baud rates up to and including 115.2 Kbits/sec, the RZI modulation scheme is used. “0” is
represented by a light pulse of 3/16th of a bit time. Some examples of signal pulse duration are
shown in
Table 35-12. IrDA Pulse Duration
Baud Rate
2.4 Kb/s
9.6 Kb/s
19.2 Kb/s
38.4 Kb/s
57.6 Kb/s
115.2 Kb/s
• Disable TX and Enable RX
• Configure the TXD pin as PIO and set it as an output to 0 (to avoid LED emission). Disable
• Receive data
the internal pull-up (better for power consumption).
Table
Transmitter
35-12.
Receiver
USART
Demodulator
Figure
Modulator
35-32. The modulator and demodulator are compliant
Pulse Duration (3/16)
78.13 μs
19.53 μs
9.77 μs
4.88 μs
3.26 μs
1.63 μs
RXD
TXD
SAM3U Series
SAM3U Series
RX
TX
Transceivers
IrDA
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