Fujitsu MB89950 Series, Hardware Manual

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207
CHAPTER 10 UART
10.4.2 Serial Rate Control Register (SRC)
The serial rate control register (SRC) is to set the UART transmission speed (baud rate).
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Serial rate control register (SRC)
Figure 10.4-3 Serial rate control register (SRC)
Address Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Initial value
0021
H
— — CR CS1 CS0 RC2 RC1 RC0 --011000
B
R/W R/W R/W R/W R/W R/W
RC2 RC1 RC0
Baud rate selection bits
Transfer clock selection bits
Clock rate selection bit
Division
ratio
Baud rate (bps )
4.9152 MHz 5 MHz Clock
1/4 1/4 1/65 PDS divi si on
1/64 1/8 1/16
CS1, CS0,
CR divi si on
0 0 0
2
0
9600 78125 2404
0 0 1
2
1
4800 39063 1202
0 1 0
2
2
2400 19531 601
0 1 1
2
3
1200 9766
300
1 0 0
2
4
600 4883
150
1 0 1
2
5
300 2441
75
1 1 0
2
6
150 1221 38
1 1 1
2
7
75 610 19
CS1 CS0
Cloc k in put CR Asynchronous Synchr onous
0 0 External clock
0 1/16
1/1
1 1/64
0 1 PWM timer
0 1/16
1/2
1 1/64
1 0
Dedicated baud
rate generator
0 1/16
1/2
1 1/64
1 1
1/8
1/1
CR
0 1/16 of clock input
1 1/64 of clock input
Note: When CS1 and CS0 = "11
B
", the 1/8 clock rate is selected irrespective
of the value of the CR bit.
R/W : Readable and writable
: Initial value
: Unused