USCI Operation: UART Mode
19-17
Universal Serial Communication Interface, UART Mode
Oversampling Baud Rate Generation
The oversampling mode is selected when UCOS16 = 1. This mode supports
sampling a UART bit stream with higher input clock frequencies. This results
in majority votes that are always 1/16 of a bit clock period apart. This mode also
easily supports IrDA pulses with a 3/16 bit-time when the IrDA encoder and
decoder are enabled.
This mode uses one prescaler and one modulator to generate the BITCLK16
clock that is 16 times faster than the BITCLK. An additional divider and
modulator stage generates BITCLK from BITCLK16. This combination
supports fractional divisions of both BITCLK16 and BITCLK for baud rate
generation. In this mode, the maximum USCI baud rate is 1/16 the UART
source clock frequency BRCLK. When UCBRx is set to 0 or 1 the first prescaler
and modulator stage is bypassed and BRCLK is equal to BITCLK16.
Modulation for BITCLK16 is based on the UCBRFx setting as shown in
Table 19−3. A 1 in the table indicates that the corresponding BITCLK16 period
is one BRCLK period longer than the periods m=0. The modulation restarts
with each new bit timing.
Modulation for BITCLK is based on the UCBRSx setting as shown in
Table 19−2 as previously described.
Table 19−3.BITCLK16 Modulation Pattern
UCBRFx
Number of BITCLK16 Clocks After Last Falling BITCLK Edge
UCBRFx
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
00h
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
01h
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
02h
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
1
03h
0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
1
04h
0
1
1
0
0
0
0
0
0
0
0
0
0
0
1
1
05h
0
1
1
1
0
0
0
0
0
0
0
0
0
0
1
1
06h
0
1
1
1
0
0
0
0
0
0
0
0
0
1
1
1
07h
0
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
08h
0
1
1
1
1
0
0
0
0
0
0
0
1
1
1
1
09h
0
1
1
1
1
1
0
0
0
0
0
0
1
1
1
1
0Ah
0
1
1
1
1
1
0
0
0
0
0
1
1
1
1
1
0Bh
0
1
1
1
1
1
1
0
0
0
0
1
1
1
1
1
0Ch
0
1
1
1
1
1
1
0
0
0
1
1
1
1
1
1
0Dh
0
1
1
1
1
1
1
1
0
0
1
1
1
1
1
1
0Eh
0
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
0Fh
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Summary of Contents for MSP430x4xx Family
Page 1: ...MSP430x4xx Family 2007 Mixed Signal Products User s Guide SLAU056G ...
Page 2: ......
Page 6: ...vi ...
Page 114: ...3 76 RISC 16 Bit CPU ...
Page 304: ...5 20 FLL Clock Module ...
Page 340: ...7 8 Supply Voltage Supervisor ...
Page 348: ...8 8 16 Bit Hardware Multiplier ...
Page 372: ...9 24 32 Bit Hardware Multiplier ...
Page 400: ...10 28 DMA Controller ...
Page 428: ...13 10 Basic Timer1 ...
Page 466: ...15 24 Timer_A ...
Page 522: ...17 30 USART Peripheral Interface UART Mode ...
Page 544: ...18 22 USART Peripheral Interface SPI Mode ...
Page 672: ...23 12 Comparator_A ...
Page 692: ...24 20 LCD Controller ...
Page 746: ...26 28 ADC12 ...