W83787IF Datasheet, PDF (43/123 Pages) Winbond – WINBOND I/O WITH SERIAL-INFRARED SUPPORT

W83787IF
4.2.8 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 2¹⁶-1. The output frequency of
the baud generator is the baud rate multiplied by 16, and this is the base frequency for the transmitter
and receiver. The following table illustrates the use of the baud generator with frequency of 1.8461
Mhz. In high speed UART mode (refer CR0C.bit7 and CR0C.bit6), the programmable baud generator
directly uses 24 MHZ and the divider which is same as normal speed divisor. In the high speed mode,
the data transmission rate can be up to 1.5 M bps.
TABLE 4-6 BAUD RATE TABLE
BAUD RATE USING 24 MHZ TO GENERATE 1.8461 MHZ
Desired Baud Rate
50
75
Decimal divisor used to
generate 16X clock
2304
1536
Percent error difference
between desired and actual
**
**
110
134.5
150
300
600
1047
857
768
384
192
0.18%
0.099%
**
**
**
1200
96
1800
64
2000
58
2400
48
3600
32
**
**
0.53%
**
**
4800
24
**
7200
16
**
9600
12
**
19200
6
**
38400
3
**
57600
2
**
115200
1
**
230400
104*
**
460800
52*
**
921600
26*
**
1.5M
1*
0%
* Only use in high speed mode (refer CR0C.bit7 and CR0C.bit6).
** The percentage error for all baud rates, except where indicated otherwise, is 0.16%.
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Publication Release Date:Sep 1995
Revision A1