CP3BT23 Datasheet, PDF (157/260 Pages) Texas Instruments – CP3BT23 Reprogrammable Connectivity Processor with Bluetooth and Dual CAN Interfaces

21.4.2 Synchronous Mode
Synchronous mode is only available for the UART0 module.
When synchronous mode is selected and the UCKS bit is
set, the UART operates from a clock received on the CKX
pin. When the UCKS bit is clear, the UART uses the clock
from the internal baud rate generator which is also driven on
the CKX pin. When the internal baud rate generator is used,
the equation for calculating the baud rate is:
where BR is the baud rate, SYS_CLK is the System Clock,
N is the value of the baud rate divisor + 1, and P is the pres-
caler divide factor selected by the value in the UnPSR reg-
ister. Oversampling is not used in synchronous mode.
Use the same procedure to determine the values of N and
P as in the asynchronous mode. In this case, however, only
integer prescaler values are allowed.
BR = ^S-----^Y----^S-----^_---^C-----^L----^K--
(2 × N × P)
Table 64 Baud Rate Programming
Baud
Rate
300
600
1200
1800
2000
2400
3600
4800
7200
9600
14400
19200
38400
56000
115200
128000
230400
345600
460800
576000
691200
806400
921600
1105920
1382400
1536000
SYS_CLK = 48 MHz SYS_CLK = 24 MHz SYS_CLK = 12 MHz SYS_CLK = 10 MHz
O
16
16
16
7
16
16
8
16
12
16
11
10
10
7
7
15
13
9
13
8
10
7
N P %err O N P %err O N P %err O N P
2000 5.0 0.00 16 2000 2.5 0.00 16 1250 2.0 0.00 13 1282 2.0
2000 2.5 0.00 16 1250 2.0 0.00 16 1250 1.0 0.00 13 1282 1.0
1250 2.0 0.00 16 1250 1.0 0.00 16 625 1.0 0.00 13 641 1.0
401 9.5 0.00 8 1111 1.5 0.01 12 101 5.5 0.01 12 463 1.0
te ^{1500 1.0 0.00 16 750 1.0 0.00 16 250 1.5 0.00 16 125 2.5}
1250 1.0 0.00 16 625 1.0 0.00 16 125 2.5 0.00 9 463 1.0
1111 1.5 0.01 12 101 5.5 0.01 11 202 1.5 0.01 11 101 2.5
625 1.0 0.00 16 125 2.5 0.00 10 250 1.0 0.00 7 119 2.5
101 5.5 0.01 11 303 1.0 0.01 11 101 1.5 0.01 10 139 1.0
le ^{125 2.5 0.00 10 250 1.0 0.00 10 125 1.0 0.00 7 149 1.0}
202 1.5 0.01 11 101 1.5 0.01 14 17 3.5 0.04 14 33 1.5
250 1.0 0.00 10 125 1.0 0.00 10 25 2.5 0.00 16 13 2.5
125 1.0 0.00 10 25 2.5 0.00 16 13 1.5 0.16 8 13 2.5
o _{49 2.5 0.04 13 33 1.0 0.10 13 11 1.5 0.10 7 17 1.5}
17 3.5 0.04 13 16 1.0 0.16 13 8 1.0 0.16 7 5 2.5
s ^{25 1.0 0.00 15 5 2.5 0.00 11 1 8.5 0.27 12 1 6.5}
16 1.0 0.16 13 8 1.0 0.16 13 4 1.0 0.16 11 4 1.0
1 15.5 0.44 10 7 1.0 0.79 10 1 3.5 0.79
b^{8 1.0 0.16 13 4 1.0 0.16 13 2 1.0 0.16 11 2 1.0}
7 1.5 0.79 12 1 3.5 0.79 14 1 1.5 0.79 7 1 2.5
7 1.0 0.79 10 1 3.5 0.79 7 1 2.5 0.79
O^{1 8.5 0.04 15 2 1.0 0.79 10 1 1.5 0.79}
%err
0.00
0.00
0.00
0.01
0.00
0.01
0.01
0.04
0.08
0.13
0.21
0.16
0.16
0.04
0.79
0.16
1.36
1.36
0.79
13 4 1.0 0.16 13 2 1.0 0.16 13 1 1.0 0.16
11 4 1.0 1.36 11 2 1.0 1.36
9 1 1.0 0.47
10 1 3.5 0.79 7 1 2.5 0.79
9 1 3.5 0.79 8 2 1.0 2.34
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