MC68HC908GP32 Datasheet, PDF (253/410 Pages) Motorola, Inc – M68HC08 Family of 8-bit microcontroller units (MCUs)

Freescale Semiconductor, Inc.
Serial Communications Interface Module (SCI)
Functional Description
To verify the start bit and to detect noise, data recovery logic takes
samples at RT3, RT5, and RT7. Table 18-2 summarizes the results of
the start bit verification samples.
Table 18-2. 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
Start bit verification is not successful if any two of the three verification
samples are logic 1s. 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 18-3 summarizes the
results of the data bit samples.
Table 18-3. 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
MC68HC908GP32•MC68HC08GP32 — Rev. 6
MOTOROLA
Serial Communications Interface Module (SCI)
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Technical Data
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