Special Control Register - VersaLogic EPM-4 Reference Manual

Special Control Register

SCR (READ/WRITE) 00E0h
D7
Reserved
Bit Mnemonic
D7-D6
D5 SB-SEL
D4-D1
D0 GPI
EPM-4 Reference Manual
D6 D5
Reserved SB-SEL
Table 10: Special Control Register Bit Assignments
Description
— Reserved — These bits have no function.
BIOS Selector Input — Indicates the status of jumper V4[1-2]
SB-SEL = 0
SB-SEL = 1
Note: This general purpose bit is read-only.
— Reserved — These bits have no function.
General Purpose Input — Indicates the status of TTL input
GPI = 0
GPI = 1
Note: This bit is a read-only bit.
D4 D3
Reserved Reserved Reserved
Jumper V4 [1-2] = Out (Master BIOS)
Jumper V4 [1-2] = In (Run Time BIOS)
Jumper V4 [3-4] = Out
Jumper V4 [3-4] = In
Special Control Register
D2 D1 D0
Reserved GPI
Reference – 39