AT91SAM9G45-EKES Atmel, AT91SAM9G45-EKES Datasheet - Page 576

• Manufacturer Part Number: AT91SAM9G45-EKES
• Description: KIT EVAL FOR AT91SAM9G45
• Manufacturer: Atmel
• Series: AT91SAM Smart ARMr
• Type: MCUr

Specifications of AT91SAM9G45-EKES

• Contents: Board
• Processor To Be Evaluated: SAM9G45
• Data Bus Width: 32 bit
• Interface Type: I2C, SPI, UART
• Maximum Operating Temperature: + 50 C
• Minimum Operating Temperature: - 10 C
• Operating Supply Voltage: 1.8 V to 3.3 V
• For Use With/related Products: AT91SAM9G45
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: Q4626953

Figure 33-14. Asynchronous Start Bit Detection
Figure 33-15. Preamble Pattern Mismatch
Figure 33-16. Manchester Error Flag
6438F–ATARM–21-Jun-10
Manchester
encoded
Manchester
Manchester
Sampling
encoded
encoded
data
(16 x)
Clock
data
data
The receiver is activated and starts Preamble and Frame Delimiter detection, sampling the data
at one quarter and then three quarters. If a valid preamble pattern or start frame delimiter is
detected, the receiver continues decoding with the same synchronization. If the stream does not
match a valid pattern or a valid start frame delimiter, the receiver re-synchronizes on the next
valid edge.The minimum time threshold to estimate the bit value is three quarters of a bit time.
If a valid preamble (if used) followed with a valid start frame delimiter is detected, the incoming
stream is decoded into NRZ data and passed to USART for processing.
Manchester pattern mismatch. When incoming data stream is passed to the USART, the
receiver is also able to detect Manchester code violation. A code violation is a lack of transition
in the middle of a bit cell. In this case, MANE flag in US_CSR register is raised. It is cleared by
writing the Control Register (US_CR) with the RSTSTA bit at 1. See
ple of Manchester error detection during data phase.
sampling points
When the start frame delimiter is a sync pattern (ONEBIT field at 0), both command and data
delimiter are supported. If a valid sync is detected, the received character is written as RXCHR
Txd
Txd
Txd
1
Manchester coding error
2
Preamble Length
3
Preamble Mismatch
4
is set to 4
Preamble Length is set to 8
Detection
Start
and Start Frame Delimiter
Preamble subpacket
were successfully
Preamble Mismatch
SFD
decoded
invalid pattern
Entering USART character area
Elementary character bit time
SFD
AT91SAM9G45
Coding Error
Manchester
Figure 33-16
detected
DATA
Figure 33-15
for an exam-
illustrates
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