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Specifications in this manual are tentative and subject to change
Clock-Asynchronous Serial I/O (UART)
Mitsubishi microcomputers
M30240 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
2.5.1.2 Transfer rate
The divide-by-16 frequency, resulting from division in the bit rate generator (BRG), becomes the transfer
rate. The count source for the transfer rate register can be selected from f1, f8, f32, and the input from
the CLK pin. Clocks f1, f8, f32 are derived by dividing the CPU’s main clock by 1, 8, and 32 respectively.
Examples of baud rate settings are shown in
Table 2.17 .
Transfer rate formulas
Table 2.18:
Example of baud rate setting
When using internal clock:
fi /16 (n+1)
fi = f1, f8, f32
n = value in UARTi bit rate generator
When using external clock:
fEXT/16 (n+1)
fEXT = input on CLKi pin
n = value in UARTi bit rate generator
Baud rate
(bps)
BRGs
count source
System clock: 12 MHz
System clock: 7.3728 MHz
BRGs set value:n
Actual time (bps)
BRGs set value:n
Actual time (bps)
600
f8
155 (9B16)
601
95 (5F16)
600
1200
f8
77 (4D16)
1202
47 (2F16)
1200
2400
f8
38 (2616)
2404
23 (1716)
2400
4800
f1
155 (9B16)
4807
95 (5F16)
4800
9600
f1
77 (4D16)
9615
47 (2F16)
9600
14400
f1
51 (3316)
14423
31 (1F16)
14400
19200
f1
38 (2616)
19230
23 (1716)
19200
28800
f1
25 (1916)
28846
15 (F16)
28800
31250
f1
23 (1716)
31250
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