Xycom XVME 200 Manual page 45

XVME-200/290 Manual
December, 1987
Connector
Signal and
Mnemonic Pin Number
1A:20
IACK*
IRQl*- 1B:24-30
IRQ7*
LWORD* lC:13
(RESERV- 2B:3
ED)
SERCLK lB:21
SERDAT 1B:22
1A:l0
SYSCLK
Table A-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, generated by an interrupter, which carry
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 of processor speed or timing. It is used
for general system timing use.
It is routed via the backplane to
signal which will
line for serial
A-4
Level seven is the
be used as the
communication bus
clock signal that