SCD1284 INTEL [Intel Corporation], SCD1284 Datasheet - Page 103

• Manufacturer Part Number: SCD1284
• Description: IEEE 1284-Compatible Parallel Interface Controller with Two High-Speed Asynchronous Serial Ports
• Manufacturer: INTEL [Intel Corporation]

6.7
Datasheet
Table 22. Baud Rate Constants — CLK = 25 MHz
Note: It is not necessary that both the receiver and transmitter of a channel be programmed to the same
}
Baud Rate Tables
Table 22
to set the designated baud rate when using five standard frequency crystals.
MHz frequency;
24
limits set by the various standards covering asynchronous communications.
another standard communications base frequency (18.432 MHz) that yields divisors with nearly
zero errors overall. However, since this frequency is below 20 MHz, performance at the higher
baud rates (76.8K and above) may be slightly lower and rates above 76.8K are not recommended.
Table 26
baud rate; the CD1284 can send and receive at different rates on the same channel.
NOTE:
1. In this and the following tables, R/T is used as a register abbreviation indicating Receive/
uses a 20-MHz frequency and shows error rates that are larger although still well within the
Transmit, followed by the register acronym.
Baud Rate
128000
150000
115200
19200
38400
56000
57600
64000
76800
return(0);
through
1200
2400
4800
9600
shows divisors for the lowest recommended operating frequency, 16 MHz.
110
150
300
600
Table 23
Table 26
uses a 20.2752-MHz frequency, which yields near-perfect bit rates.
IEEE 1284-Compatible Parallel Interface Controller — CD1284
indicate the values to be loaded into the RCOR/RBPR and TCOR/TBPR
R/TCOR
4
4
3
3
2
2
1
1
0
0
0
0
0
0
0
0
0
1
R/TBPR (Hex)
6F
51
A3
51
A3
51
A3
51
A3
51
38
36
31
29
1B
18
15
Table 22
0.02%
0.47%
0.15%
0.47%
0.15%
0.47%
0.15%
0.47%
0.15%
0.47%
0.35%
0.47%
0.35%
0.76%
0.47%
1.70%
0.80%
Table 25
Error
uses a 25-
also uses
Table
103