Serial Communications Interface Module (SCI)
Functional Description
MC68HC908GP32
•
MC68HC08GP32
—
Rev. 6
Technical Data
MOTOROLA
Serial Communications Interface Module (SCI)
251
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.
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 18-2. Start Bit Verification
RT3, RT5, and RT7
Samples
Start Bit
Verification
Noise Flag
000
Yes
0
001
Yes
1
010
Yes
1
011
No
0
100
Yes
1
101
No
0
110
No
0
111
No
0
Table 18-3. Data Bit Recovery
RT8, RT9, and RT10
Samples
Data Bit
Determination
Noise Flag
000
0
0
001
0
1
010
0
1
011
1
1
100
0
1
101
1
1
110
1
1
111
1
0
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
.
..