AT91SAM7X128 Atmel, AT91SAM7X128 Datasheet - Page 327

• 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

30.6.5.3
Figure 30-25. IrDA Demodulator Operations
6120H–ATARM–17-Feb-09
Receiver
Counter
Value
Input
MCK
RXD
IrDA Demodulator
6
Rejected
5
Pulse
4
Table 30-10. IrDA Baud Rate Error (Continued)
The demodulator is based on the IrDA Receive filter comprised of an 8-bit down counter which is
loaded with the value programmed in US_IF. When a falling edge is detected on the RXD pin,
the Filter Counter starts counting down at the Master Clock (MCK) speed. If a rising edge is
detected on the RXD pin, the counter stops and is reloaded with US_IF. If no rising edge is
detected when the counter reaches 0, the input of the receiver is driven low during one bit time.
Figure 30-25
As the IrDA mode uses the same logic as the ISO7816, note that the FI_DI_RATIO field in
US_FIDI must be set to a value higher than 0 in order to assure IrDA communications operate
correctly.
Peripheral Clock
40 000 000
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
32 768 000
40 000 000
3 686 400
20 000 000
32 768 000
3
2
6
illustrates the operations of the IrDA demodulator.
6
5
Baud Rate
4
Accepted
AT91SAM7X512/256/128 Preliminary
Pulse
57 600
38 400
38 400
38 400
38 400
19 200
19 200
19 200
19 200
9 600
9 600
9 600
9 600
2 400
2 400
2 400
3
2
1
0
107
130
130
213
260
521
853
CD
43
33
53
65
12
65
24
96
6
Baud Rate Error
0.93%
0.00%
1.38%
0.63%
0.16%
0.00%
0.16%
0.31%
0.16%
0.00%
0.16%
0.16%
0.16%
0.00%
0.03%
0.04%
Pulse Time
19.53
19.53
19.53
19.53
78.13
78.13
78.13
3.26
4.88
4.88
4.88
4.88
9.77
9.77
9.77
9.77
327