XVME-212 Manual
August, 1989
Appendix A
XYCOM STANDARD I/O ARCHITECTURE
INTRODUCTION
The purpose of this appendix is to define XYCOM’s Standard I/O Architecture for
XVME I/O modules.
This Standard I/O Architecture has been incorporated on all
programming for the entire module line. The I/O Architecture specifies the logical aspects
of bus interfaces, as opposed to the “physical” or electrical aspects as defined in the
VMEbus specifications. The module elements which are standardized by the XYCOM I/O
Architecture are the following:
1 .
Module Addressing:
Where a module
is
positioned in the I/O address
space and how software can read from it or write to it
2 .
Module Identification:
installed in a system
How software can identify which modules are
3 .
Module Operational Status: How the operator can (through software)
determine the operational condition of specific modules within the system
4 .
Interrupt Control:
How software is able to control and monitor the
capability of the module to interrupt the system
5 .
Communication between Modules: How master (host) processors and
intelligent I/O modules communicate through shared global memory or the
dual-access RAM on the modules
6 .
The I/O Kernel:
How intelligent and non-intelligent “kernels”
facilitate the operation of all XYCOM I/O modules
MODULE ADDRESSING
The XYCOM I/O Architecture Design Specification recommends that XVME modules
should be addressed within the VMEbus-defined 64K short I/O address space.
The
restriction of I/O modules to the short I/O address space provides separation of
program/data address space and the I/O address space. This convention simplifies
software design and minimizes hardware and module cost, while providing 64K of address
space for I/O modules.
A-l
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com