AT91SAM7X128 Atmel, AT91SAM7X128 Datasheet - Page 326

• Manufacturer Part Number: AT91SAM7X128
• Description: MCU 32-Bit 91S ARM7TDMI RISC 128KB Flash 1.8V/3.3V 100-Pin LQFP
• Manufacturer: Atmel

Specifications of AT91SAM7X128

• Package: 100LQFP
• Device Core: ARM7TDMI
• Family Name: 91S
• Maximum Speed: 55 MHz
• Ram Size: 32 KB
• Program Memory Size: 128 KB
• Operating Supply Voltage: 1.8|3.3 V
• Data Bus Width: 32 Bit
• Program Memory Type: Flash
• Number Of Programmable I/os: 62
• Interface Type: CAN/Ethernet/SPI/I2S/TWI/USART/USB
• On-chip Adc: 8-chx10-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 3

30.6.5.1
30.6.5.2
326
AT91SAM7X512/256/128 Preliminary
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 30-9.
Figure 30-24
Figure 30-24. IrDA Modulation
Table 30-10
the requirement on the maximum acceptable error of ±1.87% must be met.
Table 30-10. IrDA Baud Rate Error
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
• Configure the TXD pin as PIO and set it as an output at 0 (to avoid LED emission). Disable
• Receive data
the internal pull-up (better for power consumption).
Table
gives some examples of CD values, baud rate error and pulse duration. Note that
shows an example of character transmission.
Transmitter
IrDA Pulse Duration
30-9.
Output
TXD
Baud Rate
115 200
115 200
115 200
115 200
57 600
57 600
57 600
Bit Period
Start
Bit
0
1
0
1
CD
11
18
22
22
36
2
4
Pulse Duration (3/16)
78.13 µs
19.53 µs
9.77 µs
4.88 µs
3.26 µs
1.63 µs
Data Bits
0
0
Baud Rate Error
1
0.00%
1.38%
1.25%
1.38%
0.00%
1.38%
1.25%
1
16
3
0
Bit Period
Stop
6120H–ATARM–17-Feb-09
Bit
1
Pulse Time
1.63
1.63
1.63
1.63
3.26
3.26
3.26