Xycom XVME-500, Manual

Page: 75 / 104

XVME-500/590 Manual
February, 1988
Signal
Mnemonic
BR0*-BR3*
D S O *
D S l *
DTACK*
D00-D15
G N D
Table B-l. VMEbus Signal Identification (cont’d)
Connector
and
Pin Number
lB:12-15
lA:13
lA:12
lA:16
IA:1-8
lC:l-8
lA:9,11,
15,17,19,
1 B:20,23,
lC:9
2B:2,12,
22,31
Signal Name and Description
BUS REQUEST (0-3): Open-collector driven signals
generated by Requesters. These signals indicate that a
DTB master in the daisy-chain requires access to the
bus.
DATA STROBE 0: Three-state driven signal that
indicates during byte and word transfers that a data
transfer will occur on data buss lines (D00-D07).
DATA STROBE 1: Three-state driven signal that
indicates during byte and word transfers that a data
transfer will occur on data bus lines (D0-D15).
DATA TRANSFER ACKNOWLEDGE: Open-collector
driven signal generated by a DTB slave. The falling
edge of this signal indicates that valid data is available
on the data bus during a read cycle, or that data has
been accepted from the data bus during a write cycle.
D A T A
B U S ( b i t s 0 - 1 5 ) : T h r e e - s t a t e d r i v e n , b i -
directional data lines that provide a data path between
the DTB master and slave.
GROUND
B-3
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