MC68HC908LJ12CPB FREESCALE [Freescale Semiconductor, Inc], MC68HC908LJ12CPB Datasheet - Page 241

• Manufacturer Part Number: MC68HC908LJ12CPB
• Description: 8-bit microcontroller units
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Infrared Serial Communications
Technical Data
242
Infrared Serial Communications Interface Module (IRSCI)
To locate the start bit, data recovery logic does an asynchronous search
for a logic 0 preceded by three logic 1s. When the falling edge of a
possible start bit occurs, the RT clock begins to count to 16.
To verify the start bit and to detect noise, data recovery logic takes
samples at RT3, RT5, and RT7.
the start bit verification samples.
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.
results of the data bit samples.
RT8, RT9, and RT10
RT3, RT5, and RT7
Samples
Table 13-2. Start Bit Verification
Samples
Table 13-3. Data Bit Recovery
000
001
010
011
100
101
110
111
000
001
010
011
100
101
110
111
Table 13-2
Determination
Verification
Start Bit
Data Bit
Yes
Yes
Yes
Yes
No
No
No
No
0
0
0
1
0
1
1
1
Table 13-3
summarizes the results of
Noise Flag
MC68HC908LJ12
Noise Flag
Freescale Semiconductor
0
1
1
0
1
0
0
0
summarizes the
0
1
1
1
1
1
1
0
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Rev. 2.1