h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 404

• Manufacturer Part Number: h8s-2649
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 13 Serial Communication Interface (SCI)
13.3.9
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 13.2 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 or written to by the CPU at all times.
Table 13.2 The Relationships between The N Setting in BRR and Bit Rate B
[Legend]
B:
N:
φ:
n and S:
Table 13.3 shows sample N settings in BRR in normal asynchronous mode. Table 13.4 shows the
maximum bit rate for each frequency in normal asynchronous mode. Table 13.6 shows sample N
settings in BRR in clocked synchronous mode. Table 13.8 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 13.7.4, Receive Data Sampling
Timing and Reception Margin in smart card Interface Mode. Tables 13.5 and 13.7 show the
maximum bit rates with external clock input.
Rev. 2.00 Dec. 05, 2005 Page 366 of 724
REJ09B0200-0200
Mode
Asynchronous
Mode
Clocked
Synchronous
Mode
Smart Card
Interface Mode
CKS1
0
0
1
1
SMR Setting
Bit Rate Register (BRR)
Bit rate (bit/s)
BRR setting for baud rate generator (0 ≤ N ≤ 255)
Operating frequency (MHz)
Determined by the SMR settings shown in the following tables.
CKS0
0
1
0
1
BRR Setting N
N
N
N
64
S
8
2
2
2
2n 1
2n 1
2n 1
n
0
1
2
3
10
10
10
6
6
6
B
B
B
1
1
1 Error (%)
Error
Error (%)
BCP1
0
0
1
1
{
{
B
SMR Setting
B
64
S
BCP0
0
1
0
1
2
2
2n 1
2n 1
10
10
6
6
(N
(N
1)
1)
S
32
64
372
256
1 }
1 }
100
100