Specifications

Chapter 6: The VMEbus Interface
Page 71
ARBPRI Arbitration priority. This defines the level at which the EPC-5A arbitrates
for the VMEbus. 11 means 3, 10 means 2, 01 means 1, 00 means 0. Like
for RELM, altering this field via the VME-mapped location of this register
has no effect.
READY This is a RAM bit defined by the VXI specification. In a VXIbus software
environment, if READY=1 and PASS=1, the EPC-5A is ready to accept
VXI-defined messages. In the EPC-1 and in early versions of the EPC-3
manual, this bit was named EXTE. Its implementation hasn’t changed, but
it was renamed to correspond to the renaming of the bit in revision 1.3 of
the VXIbus specification.
PASS If set (1), the EPC-5A has completed its self test successfully. If this bit is
clear, the Test LED on the EPC-5A front panel is lit.
NOSF SYSFAIL inhibit. If set, the EPC-5A cannot assert the VMEbus SYSFAIL
line.
RSTP Reset EPC. Setting this bit resets the EPC-5A.
SLE Slave enable. If set, the EPC-5A responds to certain A24 or A32 accesses
on the VMEbus.
MODID This readable bit is connected to pin 30 in row A of the VMEbus P2 con-
nector. If clear (0), it denotes that the pin is being pulled high. (This is
used in VXI systems for module identification.)
SYSR SYSRESET. The EPC-5A asserts the VME SYSRESET line while this bit
is 1. When using this bit, it is the software’s responsibility to ensure that
the VME-specified minimum assertion time of SYSRESET is met.
SYSF SYSFAIL. The EPC-5A asserts the VME SYSFAIL line while this bit is 0.
(The polarity of the bit is reversed from that of SYSRESET so that an
EPC-5A 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-5A is jumpered to
be the VMEbus system controller. If set, the EPC-5A 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 Register (8146 & 8147)
11111111 Lower
00011 SLAVE BASE Upper