Special Registers
EPM-32 Reference Manual
49
Jumper and Status Register
JSR (READ/WRITE) 1D2h (or 1E2h via CMOS Setup)
D7
D6
D5
D4
D3
D2
D1
D0
GPI
VB-SEL
SB-SEL
Reserved
Reserved
WDOG_CLR
Reserved
Reserved
Table 21: Jumper and Status Register Bit Assignments
Bit
Mnemonic
Description
D7
GPI
General Purpose Input
—
Indicates the status of jumper V1[5-6] .
GPI = 0
Jumper Out
GPI = 1
Jumper In
Note:
This is a read-only bit.
D6
VB-SEL
Video BIOS Selection
— Indicates the status of jumper V1[3-4].
VB-SEL = 0
Jumper out, Secondary Video BIOS selected
VB-SEL = 1
Jumper in, Primary Video BIOS selected
Note:
This is a read-only bit.
D5
SB-SEL
System BIOS Selection
— Indicates the status of jumper V1[1-2].
SB-SEL = 0
Jumper out, Master System BIOS selected
SB-SEL = 1
Jumper in, Run Time System BIOS selected
Note:
This is a read-only bit.
D4-D3
Reserved
Reserved
— These bits have no function.
D2
WDOG_CLR
Watchdog Clear
—
Write a 1 to this bit to clear the WDOG_STA bit in the
SCR register (1D0h).
D1-D0
Reserved
Reserved
— These bits have no function.