HD6433935 Hitachi, HD6433935 Datasheet - Page 283

• Manufacturer Part Number: HD6433935
• Description: 8-Bit MICROCONTROLLER
• Manufacturer: Hitachi

8. Bit rate register (BRR)
BRR is an 8-bit register that designates the transmit/receive bit rate in accordance with the baud
rate generator operating clock selected by bits CKS1 and CKS0 of the serial mode register (SMR).
BRR can be read or written by the CPU at any time.
BRR is initialized to H'FF upon reset, and in standby, module standby, or watch mode.
Table 10-6 shows examples of BRR settings in asynchronous mode. The values shown are for
active (high-speed) mode.
Table 10-6 Examples of BRR Settings for Various Bit Rates (Asynchronous Mode) (1)
Bit Rate
(bit/s)
110
150
200
250
300
600
1200
2400
4800
9600
19200
31250
38400
Bit
Initial value
Read/Write
OSC
32.8 kHz
n
Cannot be used,
as error exceeds
3%
N
BRR7
R/W
Error
(%)
7
1
38.4 kHz
n
—
0
0
—
0
0
—
—
—
—
—
—
—
BRR6
R/W
6
1
N
—
3
2
—
1
0
—
—
—
—
—
—
—
Error
(%)
—
0
0
—
0
0
—
—
—
—
—
—
—
BRR5
R/W
5
1
2 MHz
n
—
2
0
0
0
0
0
0
—
—
—
0
—
BRR4
R/W
N
—
12
155
124
103
51
25
12
—
—
—
0
—
4
1
Error
(%)
—
0.16
0.16
0
0.16
0.16
0.16
0.16
—
—
—
0
—
BRR3
R/W
3
1
2.4576 MHz
n
2
3
3
0
3
3
2
2
0
0
0
—
0
BRR2
N
21
3
2
153
1
0
1
0
7
3
1
—
0
R/W
2
1
Error
(%)
–0.83 —
0
0
–0.26 0
0
0
0
0
0
0
0
—
0
BRR1
R/W
4 MHz
n
2
—
2
0
0
0
0
—
—
0
—
1
1
N
—
25
—
249
12
103
51
25
12
—
—
1
—
BRR0
R/W
0
1
Error
(%)
—
0.16
—
0
0.16
0.16
0.16
0.16
0.16
—
—
0
—
271