User's Manual

Theory of Operation Chapter 6
VXI-MXI User Manual 6-8 © National Instruments Corporation
Table 6-3. Transfer Responses for VMEbus Address Modifiers
AM5 AM4 AM3 AM2 AM1 AM0 Transfer Type
HHHHHHA24 supervisory block transfer
HHHHHLA24 supervisory program access
HHHHLHA24 supervisory data access
HHHLHHA24 nonprivileged block transfer
HHHLHLA24 nonprivileged program access
H H H L L H A24 nonprivileged data access
H L H H L H A16 supervisory access
H L H L H L MXIbus transparent IACK cycle
H L H L L H A16 nonprivileged access
LLHHHHA32 supervisory block transfer
LLHHHLA32 supervisory program access
L L H H L H A32 supervisory data access
L L H L H H A32 nonprivileged block transfer
L L H L H L A32 nonprivileged program access
L L H L L H A32 nonprivileged data access
Information specifying the number of bytes and which bytes are involved in a VMEbus transfer
is sent on data strobe lines DS1* and DS0*, address line A01, and the LWORD* line. During
MXIbus transfers, the same information is transferred on the Size line, and Address/Data lines 1
and 0 (AD01 and AD00). The VMEbus transfer size information is converted into MXIbus
transfer size information during a MXIbus master transfer. Table 6-4 compares this information
for the VMEbus and the MXIbus.