at91cap7e ATMEL Corporation, at91cap7e Datasheet - Page 372

• Manufacturer Part Number: at91cap7e
• Description: Customizable Microcontroller
• Manufacturer: ATMEL Corporation

29.6.5.1
Figure 29-34. IrDA Modulation
29.6.5.2
372
AT91CAP7E
IrDA Modulation
IrDA Baud Rate
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 29-9.
Figure 29-34
Table 29-10
the requirement on the maximum acceptable error of ±1.87% must be met.
Table 29-10. IrDA Baud Rate Error
Transmitter
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
Peripheral Clock
3 686 400
20 000 000
32 768 000
40 000 000
3 686 400
20 000 000
32 768 000
40 000 000
3 686 400
20 000 000
Output
TXD
Table
gives some examples of CD values, baud rate error and pulse duration. Note that
shows an example of character transmission.
Bit Period
IrDA Pulse Duration
Start
29-9.
Bit
0
1
Baud Rate
115 200
115 200
115 200
115 200
57 600
57 600
57 600
57 600
38 400
38 400
0
1
Data Bits
0
0
78.13 μs
19.53 μs
Pulse Duration (3/16)
9.77 μs
4.88 μs
3.26 μs
1.63 μs
CD
11
18
22
22
36
43
33
2
4
6
1
1
16
Baud Rate Error
3
0
Bit Period
0.00%
1.38%
1.25%
1.38%
0.00%
1.38%
1.25%
0.93%
0.00%
1.38%
Stop
Bit
1
Pulse Time
8549A–CAP–10/08
1.63
1.63
1.63
1.63
3.26
3.26
3.26
3.26
4.88
4.88