SH7720 Datasheet, PDF (670/1524 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series

Section 18 Serial Communication Interface with FIFO (SCIF)
B:
Bit rate (bits/s)
N: SCBRR setting for baud rate generator
Asynchronous mode: 0 ≤ N ≤ 255
Synchronous mode: 1 ≤ N ≤ 255
Pφ: Peripheral module operating frequency (MHz)
n:
Baud rate generator input clock (n = 0 to 3)
(See the table below for the relation between n and the clock.)
SCSMR Settings
n
Clock Source
CKS1
CKS0
0
Pφ
0
0
1
Pφ/4
0
1
2
Pφ/16
1
0
3
Pφ/64
1
1
Find the bit rate error in asynchronous mode by the following formula:
1. When sampling rate is 1/16
Error (%) =
Pφ × 10⁶
- 1 × 100
(1+N) × B × 32 × 2^2n-1
2. When sampling rate is 1/5
Error (%) =
Pφ × 10⁶
- 1 × 100
(1+N) × B × 10 × 2^2n-1
3. When sampling rate is 1/11
Error (%) =
Pφ × 10⁶
- 1 × 100
(1+N) × B × 22 × 2^2n-1
4. When sampling rate is 1/13
Error (%) =
Pφ × 10⁶
- 1 × 100
(1+N) × B × 26 × 2^2n-1
5. When sampling rate is 1/27
Error (%) =
Pφ × 10⁶
- 1 × 100
(1+N) × B × 58 × 2^2n-1
Rev. 3.00 Jan. 18, 2008 Page 608 of 1458
REJ09B0033-0300