Datasheet

Data bit D1 Error [%]=
( )
baud rate
BRCLK
×
[ ]
2x
( )
1+6 +2× UxBR+1 -1-2 × 100%=0.29%
Data bit D2 Error [%]=
( )
baud rate
BRCLK
×
[ ]
2x
( )
1+6 +3× UxBR+2 -1-3 × 100%=2.83%
Data bit D3 Error [%]=
( )
baud rate
BRCLK
×
[ ]
2x( )1+6 +4× UxBR+2 -1-4 × 100%=-1.95%
Data bit D4 Error [%]=
( )
baud rate
BRCLK
×
[ ]
2x( )1+6 +5× UxBR+3 -1-5 × 100%=0.59%
Data bit D5 Error [%]=
( )
baud rate
BRCLK
×
[ ]
2x( )1+6 +6× UxBR+4 -1-6 × 100%=3.13%
Data bit D6 Error [%]=
( )
baud rate
BRCLK
×
[ ]
2x
( )
1+6 +7× UxBR+4 -1-7 × 100%=-1.66%
Data bit D7 Error [%]=
( )
baud rate
BRCLK
×
[ ]
2x( )1+6 +8× UxBR+5 -1-8 × 100%=0.88%
Parity bit Error [%]=
( )
baud rate
BRCLK
×
[ ]
2x( )1+6 +9×UxBR+6 -1-9 × 100%=3.42%
Stop bit 1 Error [%]=
( )
baud rate
BRCLK
×
[ ]
2x
( )
1+6 +10×UxBR+6 -1-10 ×100%=-1.37%
Start bit Error [%]=
( )
baud rate
BRCLK
×
[ ]
2x
( )
1+6 +0×UxBR+0 -1-0 × 100%=2.54%
Data bit D0 Error [%]=
( )
baud rate
BRCLK
×
[ ]
2x( )1+6 +1× UxBR+1 -1-1 × 100%=5.08%
USART Operation: UART Mode www.ti.com
The results show the maximum per-bit error to be 5.08% of a BITCLK period.
18.2.6.5 Typical Baud Rates and Errors
Standard baud rate frequency data for UxBRx and UxMCTL are listed in Table 18-2 for a 32 768-Hz watch
crystal (ACLK) and a typical 1 048 576-Hz SMCLK.
The receive error is the accumulated time versus the ideal scanning time in the middle of each bit. The
transmit error is the accumulated timing error versus the ideal time of the bit period.
Table 18-2. Commonly Used Baud Rates, Baud Rate Data, and Errors
Divide by A: BRCLK = 32 768 Hz B: BRCLK = 1 048 576 Hz
Synch
Baud Rate
Max TX Max RX Max TX Max RX
A: B: UxBR1 UxBR0 UxMCTL RX Error UxBR1 UxBR0 UxMCTL
Error % Error % Error % Error %
%
1200 27.31 873.81 0 1B 03 -4/3 -4/3 ±2 03 69 FF 0/0.3 ±2
2400 13.65 436.91 0 0D 6B -6/3 -6/3 ±4 01 B4 FF 0/0.3 ±2
4800 6.83 218.45 0 06 6F -9/11 -9/11 ±7 0 DA 55 0/0.4 ±2
9600 3.41 109.23 0 03 4A -21/12 -21/12 ±15 0 6D 03 -0.4/1 ±2
19 200 54.61 0 36 6B -0.2/2 ±2
38 400 27.31 0 1B 03 -4/3 ±2
76 800 13.65 0 0D 6B -6/3 ±4
115 200 9.1 0 09 08 -5/7 ±7
486
USART Peripheral Interface, UART Mode SLAU144J–December 2004–Revised July 2013
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