XVME-212 Manual
August, 1989
Standardized Module I/O Map
The block of short I/O addresses (called the I/O Interface Block) allocated to each XVME
module is mapped with a standardized format in order to simplify-programming and data
access.
The locations of frequently used registers and module-specific identification
information are uniform.
For example, the module identification information is always found in the first 32 odd
bytes of the module memory block. These addresses are associated with the jumpered base
address (i.e., Module I.D. data address = base + odd bytes IH - 3H).
The byte located at base a 81H on each module contains a Status/Control register
which provides the results of diagnostics for verification of the module’s operational
condition.
The next area of the module I/O Interface Block (base a 82H, up to FFFH) is
module-specific, varying in size from one module to the next. It is in this area that the
module holds specific I/O status, data, and pointer registers for use with IPC protocol.
All intelligent XVME I/O modules have an area of their I/O Interface Blocks defined as
“dual access RAM.” This area of memory provides the space where XVME “slave” I/O
modules access their command blocks and where XVME “master” modules could access
their command blocks (i.e., “master” modules can also access global system memory).
The remainder of the I/O Interface Block is then allocated to various module-specific
tasks, registers, buffers, ports, etc.
Figure A-2 shows an address map of an XVME I/O module interface block, and how it
relates to the VMEbus short I/O address space. This example shows an I/O Interface Block
that occupies a 1K segment of short I/O Address Space. It should be noted that some
modules (the XVME-164 MBMM for example) will occupy up to a 4K segment of short I/O
Address Space. Notice that any location in the I/O Interface Block may be accessed by
simply using the address formula:
Module Base A Relative Offset = Desired Location
A-3
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
