Xycom XVME 590 Manual page 75

XVME-500/590 Manual
February, 1988
Connector
and
Signal
Mnemonic Pin Number
IACK* 1 A:20
l
IRQl*- 1 B:24-30
IRQ7*
LWORD* lC:l3
(RESERV- 2B:3
ED)
SERCLK lB:21
SERDAT 1 B:22
SYSCLK lA:10
Table B-l. VMEbus Signal Identification (cont'd)
Signal Name and Description
INTERRUPT ACKNOWLEDGE: Open-collector or three-
state driven signal from any master processing an
interrupt request.
slot 1, where it is looped-back to become slot 1
IACKIN* in order to start the interrupt acknowledge
daisy-chain.
INTERRUPT REQUEST (l-7): Open-collector driven
signals,
prioritized interrupt requests.
highest priority.
LONGWORD: Three-state driven signal indicates that
the current transfer is a 32-bit transfer.
RESERVED: Signal line reserved for future VMEbus
enhancements. This line must not be used.
A reserved signal which will be used as the clock for a
serial communication bus protocol which is still being
finalized.
A reserved
transmission
messages.
SYSTEM CLOCK: A constant 16-MHz
is independent from processor speed or timing.
used for general system timing use.
It is routed via the backplane to
generated by an interrupter, which carry
signal which
line for serial communication bus
B-4
Level seven is the
will be used
clock signal that
as the
It is