cop8sgr5vej8xxx National Semiconductor Corporation, cop8sgr5vej8xxx Datasheet - Page 32

• Manufacturer Part Number: cop8sgr5vej8xxx
• Description: 8-bit Cmos Rom Based And Otp Microcontrollers With 8k To 32k Memory, Two Comparators And Usart
• Manufacturer: National Semiconductor Corporation

www.national.com
8.0 USART
rates may be created by using appropriate divisors. The 16x
clock is then divided by 16 to provide the rate for the serial
shift registers of the transmitter and receiver.
Note: The entries in Table 4 assume a prescaler output of 1.8432 MHz. In the
asynchronous mode the baud rate could be as high as 987.5k.
(1.8432 MHz Prescaler Output)
TABLE 4. Baud Rate Divisors
110 (110.03)
TABLE 5. Prescaler Factors
Prescaler
(134.58)
19200
38400
Baud
134.5
Select
1200
1800
2400
3600
4800
7200
9600
Rate
00000
00001
00010
00011
150
300
600
(Continued)
Divisor − 1
Baud Rate
NO CLOCK
Prescaler
Factor
(N-1)
1046
855
767
383
191
95
63
47
31
23
15
11
FIGURE 24. USART BAUD Clock Divisor Registers
1.5
5
2
1
2
FIGURE 23. USART BAUD Clock Generation
32
Prescaler
Select
00100
00101
00110
01000
01001
01010
01011
01100
01101
10000
10001
10010
10011
10100
10101
10110
11000
11001
11010
00111
01110
01111
10111
11011
11100
11101
11110
11111
Prescaler
Factor
10.5
11.5
12.5
13.5
14.5
15.5
2.5
3.5
4.5
5.5
6.5
7.5
8.5
9.5
10
11
12
13
14
15
16
3
4
5
6
7
8
9
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