MC908AP32CFBE Datasheet, PDF (192/324 Pages) Freescale Semiconductor, Inc – The following revision history table summarizes changes contained in this document. For your convenience, the page number designators have been linked to the appropriate location.

Infrared Serial Communications Interface Module (IRSCI)
Table 12-2. Start Bit Verification
RT3, RT5, and RT7
Samples
011
100
101
110
111
Start Bit
Verification
No
Yes
No
No
No
Noise Flag
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 12-3 summarizes the results of the data bit samples.
Table 12-3. 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
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 12-4
summarizes the results of the stop bit samples.
Table 12-4. Stop Bit Recovery
RT8, RT9, and RT10
Samples
000
001
Framing
Error Flag
1
1
Noise Flag
0
1
MC68HC908AP Family Data Sheet, Rev. 4
192
Freescale Semiconductor