USCI Operation: UART Mode
19-19
Universal Serial Communication Interface, UART Mode
19.3.11
Transmit Bit Timing
The timing for each character is the sum of the individual bit timings. Using the
modulation features of the baud rate generator reduces the cumulative bit
error. The individual bit error can be calculated using the following steps.
Low−Frequency Baud Rate Mode Bit Timing
In low-frequency mode, calculate the length of bit i T
bit,TX
[i] based on the
UCBRx and UCBRSx settings:
T
bit,TX
[i]
+
1
f
BRCLK
ǒ
UCBRx
)
m
UCBRSx
[i]
Ǔ
where:
m
UCBRSx
[i]:
Modulation of bit i from Table 19−2
Oversampling Baud Rate Mode Bit Timing
In oversampling baud rate mode calculate the length of bit i T
bit,TX
[i] based on
the baud rate generator UCBRx, UCBRFx and UCBRSx settings:
T
bit,TX
[i]
+
1
f
BRCLK
ǒ
ǒ
16
)
m
UCBRSx
[i]
Ǔ @
UCBRx
)
ȍ
15
j
+
0
m
UCBRFx
[j]
Ǔ
where:
ȍ
15
j
+
0
m
UCBRFx
[j]:
Sum of ones from the corresponding row in Table 19−3
m
UCBRSx
[i]:
Modulation of bit i from Table 19−2
This results in an end-of-bit time t
bit,TX
[i] equal to the sum of all previous and
the current bit times:
t
bit,TX
[i]
+
ȍ
i
j
+
0
T
bit,TX
[j]
To calculate bit error, this time is compared to the ideal bit time t
bit,ideal,TX
[i]:
t
bit,ideal,TX
[i]
+
1
Baudrate
(
i
)
1
)
This results in an error normalized to one ideal bit time (1/baudrate):
Error
TX
[i]
+
ǒ
t
bit,TX
[i]
*
t
bit,ideal,TX
[i]
Ǔ
@
Baudrate
@
100%
Содержание MSP430x4xx Family
Страница 1: ...MSP430x4xx Family 2007 Mixed Signal Products User s Guide SLAU056G ...
Страница 2: ......
Страница 6: ...vi ...
Страница 114: ...3 76 RISC 16 Bit CPU ...
Страница 304: ...5 20 FLL Clock Module ...
Страница 340: ...7 8 Supply Voltage Supervisor ...
Страница 348: ...8 8 16 Bit Hardware Multiplier ...
Страница 372: ...9 24 32 Bit Hardware Multiplier ...
Страница 400: ...10 28 DMA Controller ...
Страница 428: ...13 10 Basic Timer1 ...
Страница 466: ...15 24 Timer_A ...
Страница 522: ...17 30 USART Peripheral Interface UART Mode ...
Страница 544: ...18 22 USART Peripheral Interface SPI Mode ...
Страница 672: ...23 12 Comparator_A ...
Страница 692: ...24 20 LCD Controller ...
Страница 746: ...26 28 ADC12 ...