The baud rate transmit/receive clock generated is either a signal scaled from the main system clock, or
a signal scaled from the clock input from the ASCK pin.
(i) Generation of baud rate transmit/receive clock by means of main system clock
The transmit/receive clock is generated by scaling the main system clock. The baud rate generated
from the main system clock is obtained with the following expression.
[Baud rate] =
where,
f
f
n
k
Table 11-5. Relation between Main System Clock and Baud Rate
Baud
Rate
MCS=1
(bps)
BRGC Set Value Error (%) BRGC Set Value Error (%) BRGC Set Value
75
–
110
06H
150
00H
300
E0H
600
D0H
1200
C0H
2400
B0H
4800
A0H
9600
90H
19200
80H
31250
74H
38400
70H
76800
60H
Remark MCS: Oscillation mode selection register (OSMS) bit 0
CHAPTER 11 SERIAL INTERFACE CHANNEL 2
f
XX
[Hz]
n
2
(k+16)
: Main system clock oscillation frequency
X
: Main system clock frequency (fx or fx/2)
XX
: Value set in TPS0 to TPS3 (1
: Value set in MDL0 to MDL3 (0
fx=5.0 MHz
MCS=0
00H
0.88
E6H
1.73
E0H
1.73
D0H
1.73
C0H
1.73
B0H
1.73
A0H
1.73
90H
1.73
80H
1.73
70H
0
64H
1.73
60H
1.73
50H
n
11)
k
14)
MCS=1
1.73
0BH
0.88
03H
1.73
EBH
1.73
DBH
1.73
CBH
1.73
BBH
1.73
ABH
1.73
9BH
1.73
8BH
1.73
7BH
0
71H
1.73
6BH
1.73
5BH
fx=4.19 MHz
MCS=0
Error (%) BRGC Set Value Error (%)
1.14
EBH
–2.01
E3H
1.14
DBH
1.14
CBH
1.14
BBH
1.14
ABH
1.14
9BH
1.14
8BH
1.14
7BH
1.14
6BH
–1.31
61H
1.14
5BH
1.14
—
1.14
–2.01
1.14
1.14
1.14
1.14
1.14
1.14
1.14
1.14
–1.31
1.14
—
155