MC68HC08AZ60A Datasheet, PDF (224/480 Pages) Motorola, Inc – Microcontrollers

Serial Communications Interface (SCI)
To determine the value of a data bit and to detect noise, recovery logic
takes samples at RT8, RT9, and RT10. Table 16-6 summarizes the
results of the data bit samples.
Table 16-6. Data Bit Recovery
RT8, RT9, and RT10 Samples
000
001
010
011
100
101
110
111
Data Bit Determination
0
0
0
1
0
1
1
1
Noise Flag
0
1
1
1
1
1
1
0
NOTE:
The RT8, RT9, and RT10 samples do not affect start bit verification. If
any or all of the RT8, RT9, and RT10 start bit samples are logic 1s
following a successful start bit verification, the noise flag (NF) is set and
the receiver assumes that the bit is a start bit.
To verify a stop bit and to detect noise, recovery logic takes samples at
RT8, RT9, and RT10. Table 16-7 summarizes the results of the stop bit
samples.
Table 16-7. Stop Bit Recovery
RT8, RT9, and RT10 Samples
000
001
010
011
100
101
110
111
Framing Error Flag
1
1
1
0
1
0
0
0
Noise Flag
0
1
1
1
1
1
1
0
Advance Information
224
Serial Communications Interface (SCI)
MC68HC08AZ60A — Rev 0.0
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