MC9S12Q FREESCALE [Freescale Semiconductor, Inc], MC9S12Q Datasheet - Page 400

• Manufacturer Part Number: MC9S12Q
• Description: Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
In
at RT5 is high. The RT5 sample sets the noise flag. Although this is a worst-case misalignment of perceived
bit time, the data samples RT8, RT9, and RT10 are within the bit time and data recovery is successful.
Figure 13-17
synchronization with the start bit time, it does set the noise flag.
400
Figure
RT CLOCK COUNT
RT CLOCK COUNT
RESET RT CLOCK
RESET RT CLOCK
Rx Input Signal
Rx input Signal
RT CLOCK
RT CLOCK
SAMPLES
SAMPLES
13-16, a large burst of noise is perceived as the beginning of a start bit, although the test sample
shows the effect of noise early in the start bit time. Although this noise does not affect proper
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0
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Figure 13-16. Start Bit Search Example 3
Figure 13-17. Start Bit Search Example 4
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PERCEIVED START BIT
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MC9S12Q128
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Rev 1.09
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PERCEIVED AND ACTUAL START BIT
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ACTUAL START BIT
Freescale Semiconductor
LSB
LSB