DF2211NP24V Renesas Technology / Hitachi Semiconductor, DF2211NP24V Datasheet - Page 449

• Manufacturer Part Number: DF2211NP24V
• Description: H8S/2200 Series, 2212 Group, USB, RTC, HSS TNP-64B; Vcc= 2.7 to 3.6 volts, Temp= -20 to 75 C; Package: PVQN0064LB-A
• Manufacturer: Renesas Technology / Hitachi Semiconductor

12.3.11 Bit Rate Register (BRR)
BRR is an 8-bit register that adjusts the bit rate. As the SCI performs baud rate generator control
independently for each channel, different bit rates can be set for each channel. Table 12.2 shows
the relationships between the N setting in BRR and bit rate B for normal asynchronous mode,
clocked synchronous mode, and Smart Card interface mode. The initial value of BRR is H'FF, and
it can be read from or written to by the CPU at all times.
Table 12.2 Relationships between the N Setting in BRR and Bit Rate B
Legend:
B:
N:
φ:
n, S: Determined by the SMR settings shown in the following tables.
×:
Table 12.3 shows sample N settings in BRR in normal asynchronous mode. Table 12.4 shows the
maximum bit rate for each frequency in normal asynchronous mode. Table 12.6 shows sample N
settings in BRR in clocked synchronous mode. Table 12.8 shows sample N settings in BRR in
Smart Card interface mode. In Smart Card interface mode, S (the number of basic clock periods in
a 1-bit transfer interval) can be selected. For details, see section 12.7.5, Receive Data Sampling
Mode
Asynchronous
mode
Clocked
synchronous
mode
Smart Card
interface mode
CKS1
0
0
1
1
Bit rate (bps)
BRR setting for baud rate generator (0 ≤ N ≤ 255)
Operating frequency (MHz)
Don’t care
SMR Setting
CKS0
0
1
0
1
ABCS
0
1
×
×
Clock Source
φ
φ/4
φ/16
φ/64
Bit Rate
B =
B =
B =
B =
64 × 2
32 × 2
8 × 2
S × 2
φ × 10
2n-1
2n+1
φ × 10
φ × 10
2n-1
2n-1
φ × 10
× (N + 1)
× (N + 1)
× (N + 1)
× (N + 1)
6
n
0
1
2
3
6
6
6
Error
Error (%) =
Error (%) =
⎯
Error (%) =
Rev.7.00 Dec. 24, 2008 Page 395 of 698
BCP1
0
0
1
1
SMR Setting
B × 64 × 2
B × 32 × 2
B × S × 2
BCP0
0
1
0
1
φ × 10
φ × 10
φ × 10
2n+1
2n-1
2n-1
× (N + 1)
× (N + 1)
× (N + 1)
6
6
6
REJ09B0074-0700
S
32
64
372
256
– 1 × 100
– 1 × 100
– 1 × 100