© National Instruments Corporation 2-1 VXI-MXI User Manual
Chapter 2
General Description
This chapter contains the physical and electrical specifications for the VXI-MXI and describes
the characteristics of key interface board components.

Electrical Characteristics

All integrated circuit drivers and receivers used on the VXI-MXI meet the requirements of the
VMEbus specification. Table 2-1 contains a list of the VMEbus signals used by the VXI-MXI
and the electrical loading presented by the circuitry on the interface board (in terms of device
types and their part numbers).
Note: Throughout this manual, an asterisk (*) following a bus signal mnemonic indicates
that the signal is active low.
Table 2-1. VXI-MXI VMEbus Signals
Driver Device Receiver Device
Bus Signals Part Number Part Number
D[31–0], A[31–1], ALS645–1 ALS645–1
AM[5–0], LWORD ALS646–1 ALS646–1
DS0*, DS1*, WRITE* F125 ALS244
AS* F125 ALS240
SYSCLK F125 –
BG[3-0]IN* – HCT273,
GAL16V8
BG[3-0]OUT* LS32 –
BBSY*, SYSFAIL*, ACFAIL* F38 ALS240
BR[3-0]*, DTACK*, BERR* F38 ALS244
SYSRESET* AS760 ALS244
IACK* F38 –
(continues)