Bitfields for OPTi 82C750 Vendetta (device 0) ECC test / I2C control:
Bit(s)	Description	)
 7	ECC test mode enable
 6	reserved
 5	reserved (1 if SDRAM enabled)
 4	I2C data output read-back (read-only)
 3	I2C clock output read-back (read-only)
 2	I2C data output (refer to file I2C.LST for more details)
 1	I2C clock output
 0	I2C control enable
SeeAlso: #00929,I2C A0h,#00935