Cancel If Power Off

The Cancel If Power Off option can be used to assist with problems encountered when going into a hibernate or suspend condition. This will cancel any requests received by the driver when going into hibernate or suspend.

The Cancel If Power Off option is controlled through bit 6 of byte 0 of the first DWORD of the ConfigData entry in the FTDIPORT.INF file. This is the same entry that contains the Baud rate table.

The first DWORD is shown in bold in the INF fragment below.

[FtdiPort232.NT.HW.AddReg]

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

Please note that this entry is byte-reversed, so MSB the DWORD reads 3F 3F 00 01 and the least significant bit is Bit 0. When disabled (no cancel on power off), the DWORD would read 3F 3F 00 01. When enabled (cancel on power off), the DWORD would read 3F 3F 00 41.

These values are held in the registry under this key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\FTDIBUS\{Device VID, PID and serial number}\0000\Device Parameters\ConfigData