Specifications

EPC-6A Hardware Reference
56
ARBPRI Arbitration priority. This defines the level at which theEPC-6A arbitrates for
the VMEbus.
Like for RELM, altering this field via the VME-mapped location of this
register has no effect.
RDY This is a RAM bit defined by the VXI specification. In a VXIbus software
environment, if RDY=1 and PASS=1, the EPC-6A is ready to accept VXI-
defined messages. The VMEbus user needn’t be concerned with this and the
next bit.
PASS This is a RAM bit defined by the VXI specification. If set (1), the EPC-6A
completed its selftest successfully.
NOSF SYSFAIL inhibit. If set, the EPC-6A cannot assert the VME SYSFAIL line.
RSTP Reset EPC. Setting this bit resets the EPC-6A.
SLE Slave enable. If set, the EPC-6A responds to certain A24 accesses on the
VMEbus.
SYSR SYSRESET. The EPC-6A asserts the VME SYSRESET line while this bit is
1. When using this bit, it is software’s responsibility to ensure that the VME
specified minimum assertion time of SYSRESET is met.
SYSF SYSFAIL. The EPC-6A asserts the VME SYSFAIL line while this bit is
0 (zero). (The polarity of the bit is reversed from that of SYSRESET so that an
EPC-6A reset—which clears this bit—causes SYSFAIL to be asserted until the
BIOS stores a 1 in this bit.)
ARBM Arbitration mode. This bit is pertinent only if the EPC-6A is jumpered to be the
VMEbus system controller. If set, the EPC-6A is a priority arbiter; otherwise
it is a round-robin arbiter. Like for RELM, altering this field via the VME-
mapped location of this register has no effect.
Slave Offset Registers (8146h and 9147H)
SLAVE BASE defines the base address of the EPC-6A’s memory in the VMEbus A24
address space as follows: 00 – 000000, 01 – 400000, 10 – 800000, 11 – C00000.
This value... Means...
11 3
10 2
01 1
00 0
Slave Offset Reg, lower
11111111
Slave Offset Reg, upper
000111SLAVE BASE