MC68HC08AS32 Datasheet, PDF (251/394 Pages) Motorola, Inc – M68HC08 Family of 8-bit microcontroller units (MCUs)

Serial Communications Interface (SCI)
Functional Description
To verify the start bit and to detect noise, data recovery logic takes
samples at RT3, RT5, and RT7. Table 17-4 summarizes the results of
the start bit verification samples.
Table 17-4. 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 17-5 summarizes the
results of the data bit samples.
Table 17-5. Data Bit Recovery
RT8, RT9, and RT10
Samples
000
001
010
011
100
101
110
111
Data Bit
Determination
Noise Flag
0
0
0
1
0
1
1
1
0
1
1
1
1
1
1
0
MC68HC08AS32 — Rev. 3.0
MOTOROLA
Serial Communications Interface (SCI)
Advance Information
251