Receiver
MSC8144E Reference Manual, Rev. 3
Freescale Semiconductor
20-17
In Figure 20-16, a noise burst makes the majority of data samples RT8, RT9, and RT10 high.
This sets the noise flag but does not reset the RT counter. In the start bits only, the RT8, RT9, and
RT10 data samples are not used for determining bit value.
20.2.3 Framing Error
If the data sampling logic does not detect a logic 1 where the stop bit should be in an incoming
frame, it sets the framing error flag, SCISR[FE]. A break character also sets the FE flag because a
break character has no stop bit. The FE flag is set at the same time that the RDRF flag is set. FE
inhibits further data reception until it is cleared. Clear SCISR[FE] by reading SCISR and then
reading the SCIDR.
Figure 20-15. Start Bit Search Example 6
Figure 20-16. Start Bit Search Example 7
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
2
RT
3
RT
4
RT
7
RT
6
RT
5
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
Start Bit
1
1
1
1
1
0
1
0
LSB
1
1
1
1
1 0
0
0
0
0
0
0
0
No Start Bit Found
Reset RT Counter
Samples
RT Clock
RT Clock Count
URXD
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
1
RT
2
RT
3
RT
4
RT
7
RT
6
RT
5
RT
1
0
RT
9
RT
8
RT
1
4
RT
1
3
RT
1
2
RT
1
1
RT
1
5
RT
1
6
RT
1
RT
2
RT
3
Start Bit
1
1
1
1
1
0
0
0
LSB
1
1
1
1
0 1
1
0
Reset RT Counter
Samples
RT Clock
RT Clock Count
URXD
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...