MC9S12T64 Datasheet, PDF (444/608 Pages) Motorola, Inc – Specification

Freescale Semiconductor, Inc.
Serial Communications Interface (SCI)
RX Input Signal
START BIT
LSB
SAMPLES 1 1 1 1 1 1 1 1 0
0
0
0000
RT CLOCK
RT CLOCK COUNT
RESET RT CLOCK
START BIT
QUALIFICATION
START BIT
DATA
VERIFICATION SAMPLING
Figure 80 Receiver Data Sampling
To verify the start bit and to detect noise, data recovery logic takes
samples at RT3, RT5, and RT7. Table 77 summarizes the results of the
start bit verification samples.
Table 77 Start Bit Verification
RT3, RT5, and RT7 Samples
000
001
010
011
100
101
110
111
Start Bit Verification
Yes
Yes
Yes
No
Yes
No
No
No
Noise Flag
0
1
1
0
1
0
0
0
If start bit verification is not successful, the RT clock is reset and a new
search for a start bit begins.
To determine the value of a data bit and to detect noise, recovery logic
takes samples at RT8, RT9, and RT10. Table 78 summarizes the results
of the data bit samples.
MC9S12T64Revision 1.1.1
Serial Communications Interface (SCI)
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