mc68hc908gr8a Freescale Semiconductor, Inc, mc68hc908gr8a Datasheet - Page 141

no-image

mc68hc908gr8a

Manufacturer Part Number
mc68hc908gr8a
Description
M68hc08 Microcontrollers Microcontroller
Manufacturer
Freescale Semiconductor, Inc
Datasheet
To determine the value of a data bit and to detect noise, recovery logic takes samples at RT8, RT9, and
RT10.
To verify a stop bit and to detect noise, recovery logic takes samples at RT8, RT9, and RT10.
summarizes the results of the stop bit samples.
13.4.3.4 Framing Errors
If the data recovery logic does not detect a 1 where the stop bit should be in an incoming character, it sets
the framing error bit, FE, in SCS1. A break character also sets the FE bit because a break character has
no stop bit. The FE bit is set at the same time that the SCRF bit is set.
Freescale Semiconductor
Table 13-3
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 1s following a
successful start bit verification, the noise flag (NF) is set and the receiver
assumes that the bit is a start bit.
summarizes the results of the data bit samples.
RT8, RT9, and RT10
MC68HC908GR8A • MC68HC908GR4A Data Sheet, Rev. 5
RT8, RT9, and RT10
Samples
Samples
000
001
010
011
100
101
110
111
000
001
010
011
100
101
110
111
Table 13-4. Stop Bit Recovery
Table 13-3. Data Bit Recovery
NOTE
Determination
Error Flag
Data Bit
Framing
0
0
0
1
0
1
1
1
1
1
1
0
1
0
0
0
Noise Flag
Noise Flag
0
1
1
1
1
1
1
0
0
1
1
1
1
1
1
0
Functional Description
Table 13-4
141

Related parts for mc68hc908gr8a