AT32UC3A4256 Atmel Corporation, AT32UC3A4256 Datasheet - Page 563

• Manufacturer Part Number: AT32UC3A4256
• Manufacturer: Atmel Corporation

Specifications of AT32UC3A4256

• Flash (kbytes): 256 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 66 MHz
• Cpu: 32-bit AVR
• Hardware Qtouch Acquisition: No
• Usb Transceiver: 1
• Usb Speed: Hi-Speed
• Usb Interface: Device + OTG
• Spi: 6
• Twi (i2c): 2
• Uart: 4
• Ssc: 1
• Sd / Emmc: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 128
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 3.0 to 3.6
• Operating Voltage (vcc): 3.0 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 6
• Output Compare Channels: 6
• Input Capture Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

25.6.3.12
25.6.3.13
32072G–11/2011
Framing Error
Transmit Break
The receiver is capable of detecting framing errors. A framing error has occurred if a stop bit
reads as zero. This can occur if the transmitter and receiver are not synchronized. A framing
error is reported by CSR.FRAME as soon as the error is detected, at the middle of the stop bit.
Figure 25-24. Framing Error Status
When TXRDY is set, the user can request the transmitter to generate a break condition on the
TXD line by writing a one to The Start Break bit (CR.STTBRK). The break is treated as a normal
0x00 character transmission, clearing TXRDY and TXEMPTY, but with zeroes for preambles,
start, parity, stop, and time guard bits. Writing a one to the Stop Break bit (CR.STBRK) will stop
the generation of new break characters, and send ones for TG duration or at least 12 bit periods,
ensuring that the receiver detects end of break, before resuming normal operation.
illustrates STTBRK and STPBRK effect on the TXD line.
Writing to STTBRK and STPBRK simultaneously can lead to unpredictable results. Writes to
THR before a pending break has started will be ignored.
Baud Rate (bit/sec)
200000
Baud Rate
14400
19200
28800
33400
56000
57600
9 600
FRAME
RXRDY
Clock
Write
RXD
CR
Start
Bit
D0
D1
D2
D3
Bit Time (µs)
D4
104
D5
69
52
35
30
18
17
5
D6
D7
Parity
Bit
Stop
Bit
RSTSTA = 1
Time-out (ms)
6 827
4 551
3 413
2 276
1 962
1 170
1 138
328
Figure 25-25
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