MSC8113 Reference Manual, Rev. 0
21-14
Freescale Semiconductor
UART
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
(logic 0).
To verify a stop bit and to detect noise, sample logic takes samples at RT8, RT9, and RT10. The
noise flag, NF, is set if not all samples have the same logical value (the same as for data bit
sampling). If the majority of the samples are logic 0 framing error flag, FE, is set. Table 21-6
summarizes the results of the stop bit samples.
In Figure 21-10 the start bit verification samples RT3 and RT5 determine that the first logic 0
detected is noise and not the beginning of a start bit. The RT counter is reset and the start bit
search resumes. The noise flag is not set because the noise occurred before the start bit was
found.
Table 21-6. Stop Bit Recovery
RT8, RT9, and RT10 Samples
Framing Error Flag
Noise Flag
000
1
0
001
1
1
010
1
1
011
0
1
100
1
1
101
0
1
110
0
1
111
0
0
Figure 21-10. Start Bit Search Example 1
Reset RT Counter
RT
1
RT
1
RT
1
RT
1
RT
2
RT
3
RT
4
RT
5
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
Samples
RT Clock
RT Clock Count
Start Bit
URXD
1
1
0
1
1
1 1
0
0
0
0
0
LSB
0
0
Summary of Contents for MSC8113
Page 1: ...MSC8113 Reference Manual Tri Core 16 Bit Digital Signal Processor MSC8113RM Rev 0 May 2008 ...
Page 20: ...MSC8113 Reference Manual Rev 0 xx Freescale Semiconductor Contents ...
Page 28: ...MSC8113 Reference Manual Rev 0 xxviii Freescale Semiconductor ...
Page 56: ...MSC8113 Reference Manual Rev 0 1 28 Freescale Semiconductor MSC8113 Overview ...
Page 76: ...MSC8113 Reference Manual Rev 0 2 20 Freescale Semiconductor SC140 Core Overview ...
Page 134: ...MSC8113 Reference Manual Rev 0 4 30 Freescale Semiconductor System Interface Unit SIU ...
Page 168: ...MSC8113 Reference Manual Rev 0 6 18 Freescale Semiconductor Boot Program ...
Page 180: ...MSC8113 Reference Manual Rev 0 7 12 Freescale Semiconductor Clocks ...
Page 260: ...MSC8113 Reference Manual Rev 0 8 80 Freescale Semiconductor Memory Map ...
Page 300: ...MSC8113 Reference Manual Rev 0 9 40 Freescale Semiconductor Extended Core ...
Page 304: ...MSC8113 Reference Manual Rev 0 10 4 Freescale Semiconductor MQBus and M2 Memory ...
Page 308: ...MSC8113 Reference Manual Rev 0 11 4 Freescale Semiconductor SQBus ...
Page 590: ...MSC8113 Reference Manual Rev 0 17 46 Freescale Semiconductor Interrupt Processing ...
Page 614: ...MSC8113 Reference Manual Rev 0 18 24 Freescale Semiconductor Debugging ...
Page 622: ...MSC8113 Reference Manual Rev 0 19 8 Freescale Semiconductor Internal Peripheral Bus IPBus ...
Page 724: ...MSC8113 Reference Manual Rev 0 21 32 Freescale Semiconductor UART ...
Page 920: ...MSC8113 Reference Manual Rev 0 25 150 Freescale Semiconductor Ethernet Controller ...
Page 1171: ...MSC8113 Reference Manual Rev 0 Freescale Semiconductor C 61 EF wait_rts P 01077FFC 9F rts 71 ...
Page 1172: ...MSC8113 Reference Manual Rev 0 C 62 Freescale Semiconductor MSC8113 Boot Code ...
Page 1202: ...MSC8113 Reference Manual Rev 0 Index 30 Freescale Semiconductor Index ...