HD6417144 RENESAS [Renesas Technology Corp], HD6417144 Datasheet - Page 460

• Manufacturer Part Number: HD6417144
• Description: 32-Bit RISC Microcomputer SuperHTM RISC engine Family/SH7144 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

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 the effective bit rate B
clocked synchronous, and smart card interface modes. The initial value of BRR is H'FF, and it can
be read from or written to by the CPU at all times.
Table 13.2 Relationships between N Setting in BRR and Effective Bit Rate B
[Legend]
B
B
N:
Pφ:
n and S:
Rev.4.00 Mar. 27, 2008 Page 416 of 882
REJ09B0108-0400
Mode
Asynchronous mode
(n = 0)
Asynchronous mode
(n = 1 to 3)
Clocked synchronous
mode (n = 0)
Clocked synchronous
mode (n = 1 to 3)
Smaet card interface
mode (n = 0)
Smaet card interface
mode (n = 1 to 3)
0
1
:
:
Effective bit rate (bit/s) Actual transfer speed according to the register settings
Logical bit rate (bit/s) Specified transfer speed of the target system
BRR setting for baud rate generator (0 ≤ N ≤ 255)
Peripheral clock operating frequency (MHz)
Bit Rate Register (BRR)
Determined by the SMR settings shown in the following tables.
Bit Rate
B
B
B
B
B
B
0
0
0
0
0
0
=
=
=
=
=
=
32 × 2
S × 2
S × 2
4 × 2
32 × 2
4 × 2
Pφ × 10
Pφ × 10
Pφ × 10
Pφ × 10
Pφ × 10
Pφ × 10
2n+1
2n+1
2n+2
2n+1
2n
2n
× (N + 1)
× (N + 1)
× (N + 1)
× (N + 1)
× (N + 1)
× (N + 1)
6
6
6
6
6
6
Error
Error (%) =
Error (%) =
—
—
Error (%) =
Error (%) =
⎞
⎠
⎞
⎠
⎞
⎠
⎞
⎠
B
B
B
B
B
B
B
B
0
for asynchronous,
0
1
0
1
0
1
0
1
– 1 × 100
– 1 × 100
– 1 × 100
– 1 × 100
⎞
⎠
⎞
⎠
⎞
⎠
⎞
⎠
0