Specifications

8.1 Status & Control Register 0 (I/O address 210h)
765 43 2 1 0
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CONSOLE USER BYTE BYTE BYTE BOARD BOARD BOARD
SWITCH SWITCH SWAP SWAP SWAP REV 2 REV 1 REV 0
Bits2-0:Hardware Revision Strapping (Read Only)
000 = Rev A
001 = Rev B Etc...
Bits5-3:VMEHardware Byte Swapping (Read/Write)
Bit 3: VME Byte Swapping for Master (0=off, 1=on)
Bit 4: VME Byte Swapping for Slave (0=off, 1=on)
Bit 5: VME Fast Byte Swapping i.e Partial Cycle Type Decode (0=off, 1=on)
Byte swapping is only supported for aligned transfers. When swapping is enabled, the hardware
will normally decode the VME cycle type as it takes place to determine if swapping is possible. It
then configures a set of multiplexors to perform the swap. To meet the VME bus timing
specifications for write cycles it is necessary to delay the cycle while the multiplexors are
configured. Setting bit 5 of this register turns off the delay, but should only be done if all VME
cycles are guaranteed swappable.
Bit 6: User Switch (Read Only)
Available for user defined purposes in BIOS mode. In VSA mode this switch is used for factory
test.
0 = Switch off
1 = Switch on
Bit 7: Console Switch (Read Only)
Used to define the BIOS default standard input/output mode. This bit indicates the setting of the
Console Mode switch (see Section 6.1).
0 = Input/output via COM 1
1 = Input via keyboard/output via VGA PMC adapter
VP 110/01x 8-3
Additional Local I/O Functions