*[FtdiPort232.NT.HW.AddReg]*

HKR,,ConfigData,1,01,00,3F,3F,

HKR,,ConfigData,1,01,00,3F,3F,

*10,27**,88,13,*

*C4,09**,E2,04,*

*71,02**,38,41,*

*9c,80**,4E,C0,*

*34,00**,1A,00,*

*0D,00**,06,40,*

*03,80**,00,00,*

*d0,80*Each field consists of a pair of bytes, ordered as follows: Byte0,Byte1. Bits 13 through 0 denote the integer divisor while bits 16, 15 and 14 denote the sub-integer divisor, as follows

15,14 = 00 - sub-integer divisor = 0

15,14 = 01 - sub-integer divisor = 0.5

15,14 = 10 - sub-integer divisor = 0.25

15,14 = 11 - sub-integer divisor = 0.125

The divisor can be extracted for each entry in a few simple steps, as shown here for the entry 9c,80

Step 1 - re-order the bytes: 9c,80 => 809c Hex

Step 2 - extract the sub-integer divisor; 15 = 1, 14 = 0 => sub-integer = 0.25

Step 3 - extract the integer divisor: 13:0 = 009c Hex = 156 Dec

Step 4 - combine the integer and sub-integer divisors: 156.25 Dec

Step 5 - divide 3000000 by the divisor=> 3000000/156.25 = 19,200 baud

The following lists the standard values and their respective baud rates.

10,27 => divisor = 10000, rate = 300

88,13 => divisor = 5000, rate = 600

C4,09 => divisor = 2500, rate = 1200

E2,04 => divisor = 1250, rate = 2,400

71,02 => divisor = 625, rate = 4,800

38,41 => divisor = 312.5, rate = 9,600

9C,80 => divisor = 156, rate = 19,230

4E,C0 => divisor = 78, rate = 38,461

34,00 => divisor = 52, rate = 57,692

1A,00 => divisor = 26, rate = 115,384

0D,00 => divisor = 13, rate = 230,769

06,40 => divisor = 6.5, rate = 461,538

03,80 => divisor = 3.25, rate = 923,076

00,00 => RESERVED

D0,80 => divisor = 208.25, rate = 14406

To alias a baud rate of 920k baud to the standard 56k baud menu option under windows:

- change the 34,00 entry to 03,80 (simple as both of the values are available from the previous list)

To alias a rate of 197k baud to the standard 4,800 baud menu option under windows :

- find the best divisor, check that it is sufficiently accurate and then modify the appropriate INF file entry.

3,000,000/197,000 = 15.228. The best divisor is 15.25.

3,000,000/15.25 = 196,721. 196,721/197,000 = 99.8%. This is well within the required 3% tolerance.

Set bit 15:14 to 10 for a sub-integer divisor of 0.25, and the lower bits to 0F.

- replace the 71,02 entry with 0F,80.

Incorporating these two changes the FTDIPORT.INF entry becomes

*[FtdiPort232.NT.HW.AddReg]*

HKR,,ConfigData,1,01,00,3F,3F,10,27,88,13,C4,09,E2,04,

HKR,,ConfigData,1,01,00,3F,3F,10,27,88,13,C4,09,E2,04,

*0F,80**,38,41,9C,80,4E,C0,*

*03,80**,1A,00,0D,00,06,40,03,80,00,00,00,00*

This is for Windows 2000 and XP, the changes should be repeated in the Windows 98/ME entry also.