MC68HC908AS60ACFN FREESCALE [Freescale Semiconductor, Inc], MC68HC908AS60ACFN Datasheet - Page 187

• Manufacturer Part Number: MC68HC908AS60ACFN
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

To verify the start bit and to detect noise, data recovery logic takes samples at RT3, RT5, and RT7.
18-5
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.
Freescale Semiconductor
summarizes the results of the start bit verification samples.
Table 18-6
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.
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
RT8, RT9, and RT10 Samples
summarizes the results of the data bit samples.
RT3, RT5, and RT7 Samples
000
001
010
011
100
101
110
111
000
001
010
011
100
101
110
111
Table 18-5. Start Bit Verification
Table 18-6. Data Bit Recovery
NOTE
Data Bit Determination
Start Bit Verification
Yes
Yes
Yes
Yes
No
No
No
No
0
0
0
1
0
1
1
1
Noise Flag
Noise Flag
0
1
1
0
1
0
0
0
0
1
1
1
1
1
1
0
Functional Description
Table
187