w83977ctf Winbond Electronics Corp America, w83977ctf Datasheet - Page 62

• Manufacturer Part Number: w83977ctf
• Description: Winbond I/o
• Manufacturer: Winbond Electronics Corp America

3.2.8 Programmable Baud Generator (BLL/BHL) (Read/Write)
Two 8-bit registers, BLL and BHL, compose a programmable baud generator that uses 24 MHz to
generate a 1.8461 MHz frequency and divides it by a divisor from 1 to 2
the baud generator is the baud rate multiplied by 16, and this is the base frequency for the transmitter
and receiver. The table in the next page illustrates the use of the baud generator with a frequency of
1.8461 MHz. In high-speed UART mode (refer to CR0C bit7 and CR0C bit6), the programmable
baud generator directly uses 24 MHz and the same divisor as the normal speed divisor. In high-
speed mode, the data transmission rate can be as high as 1.5 Mbps.
3.2.9 User-defined Register (UDR) (Read/Write)
This is a temporary register that can be accessed and defined by the user.
TABLE 3-5 BAUD RATE TABLE
** The percentage error for all baud rates, except where indicated otherwise, is 0.16%.
Note. Pre-Divisor is determined by CRF0 of UART A and B.
1.8461M Hz
Pre-Div: 13
115200
19200
38400
57600
134.5
1200
1800
2000
2400
3600
4800
7200
9600
110
150
300
600
50
75
Pre-Div:1.625
14.769M Hz
153600
307200
460800
921600
14400
16000
19200
28800
38400
57600
76800
1076
1200
2400
4800
9600
400
600
880
BAUD RATE FROM DIFFERENT PRE-DIVIDER
Pre-Div: 1.0
1497600
24M Hz
124800
249600
499200
748800
1478.5
15600
23400
26000
31200
46800
62400
93600
1430
1950
3900
7800
650
975
-53 -
Decimal divisor used
to generate 16X
clock
2304
1536
1047
857
768
384
192
96
64
58
48
32
24
16
12
6
3
2
1
Publication Release Date: March 1999
16
W83977EF/ CTF
-1. The output frequency of
Error Percentage between
desired and actual
PRELIMINARY
0.099%
0.18%
0.53%
**
**
**
**
**
**
**
**
**
**
**
**
**
**
**
**
Revision A1