MC9S12T64 Datasheet, PDF (448/608 Pages) Motorola, Inc – Specification

Freescale Semiconductor, Inc.
Serial Communications Interface (SCI)
by three high samples that would qualify as a falling edge. Depending on
the timing of the start bit search and on the data, the frame may be
missed entirely or it may set the framing error flag.
RX Input Signal
START BIT
LSB
NO START BIT FOUND
SAMPLES 1 1 1 1 1 1 1 1 1 0
0
1
100000000
RT CLOCK
RT CLOCK COUNT
RESET RT CLOCK
Figure 85 Start Bit Search Example 5
In Figure 86, a noise burst makes the majority of data samples RT8,
RT9, and RT10 high. This sets the noise flag but does not reset the RT
clock. In start bits only, the RT8, RT9, and RT10 data samples are
ignored.
RX Input Signal
START BIT
LSB
SAMPLES 1 1 1 1 1 1 1 1 1 0
0
0
0101
RT CLOCK
RT CLOCK COUNT
RESET RT CLOCK
Figure 86 Start Bit Search Example 6
MC9S12T64Revision 1.1.1
Serial Communications Interface (SCI)
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