The communications driver supports very high baud rates, such as 128,000 and 57600, by interpreting the BaudRate member of the DCB structure as a baud-rate index whenever the high byte of the member is 0xFF. The driver that ships with the DDK has a maximum baud rate of 57600. In such cases, BaudRate can be one of the following values.
| Value | Baud rate |
| CBR_110 (0xFF10) | 110 |
| CBR_300 (0xFF11) | 300 |
| CBR_600 (0xFF12) | 600 |
| CBR_1200 (0xFF13) | 1200 |
| CBR_2400 (0xFF14) | 2400 |
| CBR_4800 (0xFF15) | 4800 |
| CBR_9600 (0xFF16) | 9600 |
| CBR_14400 (0xFF17) | 14400 |
| CBR_19200 (0xFF18) | 19200 |
| CBR_38400 (0xFF1B) | 38400 |
| CBR_56000 (0xFF1F) | 56000 |
| CBR_128000 (0xFF23) | 128,000 |
| CBR_256000 (0xFF27) | 256,000 |
Note:
The CBR_ values are for standardization; drivers are not required to support all indexed baud rates.
If the high byte of the BaudRate member is not 0xFF, the BaudRate member specifies the actual baud rate for the communications device. In other words, values in the range 2 through 65,279 (0xFEFF) are interpreted as baud-rate values, not as indexes. This ensures compatibility with existing communications drivers.