Bitfields for AIC-78xx device configuration register (DEVCONFIG):
Bit(s)	Description	)
 15-11	reserved
 10	(AIC-787x+) multi-port mode (MPORTMODE)
 9	(AIC-787x+) external SRAM present? (RAMPSM)
 8	"VOLSENSE"
 7	SCB RAM select (SCBRAMSEL)
 6	"MRDCEN"
 5	(AIC-787x+) external SCB SRAM access time  (EXTSCBTIME)
 4	(AIC-787x+) external SCB SRAM parity enable (EXTSCBPEN)
 3	"BERREN"
 2	"DACEN"
 1	SCSI terminator power level (STPWLEVEL)
 0	(AIC-787x+) differential active negation enable (DIFACTNEGEN)
Note:	clearing bit 7 allows access to the external SCB SRAM
SeeAlso: #01241